Re: Anyone in the Group a Degreed Metallurgist?
Springfield and LRB both offer lugged receivers. You can see them on their websites. I will gladly post photos of a welded receiver, if you want to see it. Lugging was started in the mid? eighties to prolong the bedding. With a lugged receiver, the bedding was good for the life of the barrel. Otherwise, (in a serious competition rifle), the bedding would need to be redone at least once a year.? I shot for the All National Guard Team from 1988 to 2003. At that time, each of the 3 major teams had different philosophies about lugging and bedding. The US Army? Marksmanship Unit at Ft. Benning, did not believe in lugging, they physically glued the receiver into the stock. The All National Guard Marksmanship Unit at Nashville and later Little Rock, used rear lugs and release agent when bedding. The Marine Corps Weapon Training Battalion at Quantico used double lugs ( one at front and rear) and release agent when bedding. We all went to the same matches (i.e. Interservice, Camp Perry, etc.) and no one knew who was going to win, so from my view, all philosophies are valid. For civilian competitors lugging was preferred, so they would not have the expense of rebedding each year.?
Thanx and Good Shootin'
Derrick Martin
ask_derrick@...
On Saturday, May 18, 2024 at 03:59:57 PM MST, Nick Andrews <nickjandrews@...> wrote:
Me too.? I have a couple destined for conversion into BM-59s.? That will involve milling on the receiver.?
I also have a couple of receiver forgings that might at some point ask to be finished.
Derrick
You have me curious. I have been shooting M1's for many years and never heard of this procedure.
What is the reasoning behind it?
Could you post a picture of what you are doing to the recievers?
Thanks
Erik A
Thank you for the response.
I am mildly familiar with what you discussed on how steels are hardened and the perils of Hydrogen contamination , thru other projects and advisors.
Here is my dilemma, if you can assist, it would be appreciated.
For about 30 years, I have been working on M-1 and M1A rifles. One of the tasks is to weld a recoil lug onto the rear of the receiver. I had a certified welder and he developed the process with the assistance of? the Metallurgy
Department at his day job. He commented on the process several times, but I never wrote it down. He died suddenly, and I am now trying to remember/recreate the process to work with a new welder.
The receivers are carburized 8620, the lugs are 1018, rod is Linde 65, this I know. My memory of the procedure is to tack the lug in two corners, preheat to 800degF, weld the lug in one pass on each side and then water quench.
We had done several hundred receivers, without any failures and I know the process worked. Mostly, I am looking for validation that I remember the process correctly.?
Can you assist?
I've noted that there is a deafening silence from qualified metallurgists, so as a chartered mechanical engineer, I'll advise what little I know on this subject.? NO specialist
is going to proffer free advice or any advice that allows you to proceed safely without a.) knowledge of what the steel consists of, b.) the application, including stresses, safety implications etc. and c.) professional indemnity insurance, so what follows
will deliberately be vague while explaining the difficulties against which you are up.
?
The standard advice to welders who want to weld high strength steels is just don't.? If steel is heat treated, it implies that there was some objective in heat treating it,
such as hardening, and therefore it is at least medium if not high strength.
?
That instruction can be qualified to some extent by someone with a higher level of qualification.
?
Steel that is nominally not hardenable by heat treatment is close to pure iron and is referred to as mild steel.? This is used for structures, boilers, etc. and the whole point
is that the steel and its weld are ductile.
?
To make it hardenable, various alloying elements are added, the most basic of which is carbon.? This allows the formation of iron carbide, which is very hard.? To achieve maximum
hardness, this requires a very quick quench, so you cannot through harden thick sections.? To slow down the quench requirements and allow thicker sections to be through hardened various other alloying elements can be added, such as Chromium, Vanadium, Cobalt,
Nickel, Manganese etc. ?(Manganese is in virtually all steel anyway, just as a means of mopping up impurities like Phosphorous and Sulphur.? In higher quantities than required to balance the impurities, it leads to extreme work hardening.)
?
In the periodic table of elements, Hydrogen is grouped with the metals.? It is soluble in liquid iron.? For reasons I don't understand, it doesn't cause so much of a problem
in thin mild steel, but in hardenable steel, or even thick mild steel, it comes out of solution during the solidification process and congregates at the grain boundaries, so the grains are not stuck together as well, thereby causing gross lack of strength.
?There is a limit to the % carbon in the steel beyond which you just cannot successfully weld.? Each alloying element is given a carbon equivalent, usually less than 1.? You add all those up in proportion to their % in the composition and add them to the carbon
%.? At a lower figure than the limit, welding can be successful but only if a suitable procedure is devised and followed.? This typically includes the exclusion of hydrogen (moisture, which is why rods are baked for extensive periods), preheating the job for
a period to a specified temperature, maintaining a certain minimum temperature during the welding, maintaining a specified temperature for a significant period after the welding to allow the hydrogen to diffuse out of the job, which it does only slowly, and
finally cooling very slowly.? This is fine if you don't mind losing all the high strength properties as a result of the slow cooling.? Never gone further than this myself, but it may then be possible to reharden the whole job in the normal way.
?
Very sorry, but I feel you're going to have to pay a pro for a procedure if the job is critical, or try some of the above and test it if a few failures are of little consequence.
?There should be info on t'interweb thingy about carbon equivalents and limits.
?
Eddie
?
?
------ Original Message ------
From: ask_derrick=[email protected]
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
Re: Anyone in the Group a Degreed Metallurgist?
Me too.? I have a couple destined for conversion into BM-59s.? That will involve milling on the receiver.?
I also have a couple of receiver forgings that might at some point ask to be finished.
Derrick
You have me curious. I have been shooting M1's for many years and never heard of this procedure.
What is the reasoning behind it?
Could you post a picture of what you are doing to the recievers?
Thanks
Erik A
Thank you for the response.
I am mildly familiar with what you discussed on how steels are hardened and the perils of Hydrogen contamination , thru other projects and advisors.
Here is my dilemma, if you can assist, it would be appreciated.
For about 30 years, I have been working on M-1 and M1A rifles. One of the tasks is to weld a recoil lug onto the rear of the receiver. I had a certified welder and he developed the process with the assistance of? the Metallurgy
Department at his day job. He commented on the process several times, but I never wrote it down. He died suddenly, and I am now trying to remember/recreate the process to work with a new welder.
The receivers are carburized 8620, the lugs are 1018, rod is Linde 65, this I know. My memory of the procedure is to tack the lug in two corners, preheat to 800degF, weld the lug in one pass on each side and then water quench.
We had done several hundred receivers, without any failures and I know the process worked. Mostly, I am looking for validation that I remember the process correctly.?
Can you assist?
I've noted that there is a deafening silence from qualified metallurgists, so as a chartered mechanical engineer, I'll advise what little I know on this subject.? NO specialist
is going to proffer free advice or any advice that allows you to proceed safely without a.) knowledge of what the steel consists of, b.) the application, including stresses, safety implications etc. and c.) professional indemnity insurance, so what follows
will deliberately be vague while explaining the difficulties against which you are up.
?
The standard advice to welders who want to weld high strength steels is just don't.? If steel is heat treated, it implies that there was some objective in heat treating it,
such as hardening, and therefore it is at least medium if not high strength.
?
That instruction can be qualified to some extent by someone with a higher level of qualification.
?
Steel that is nominally not hardenable by heat treatment is close to pure iron and is referred to as mild steel.? This is used for structures, boilers, etc. and the whole point
is that the steel and its weld are ductile.
?
To make it hardenable, various alloying elements are added, the most basic of which is carbon.? This allows the formation of iron carbide, which is very hard.? To achieve maximum
hardness, this requires a very quick quench, so you cannot through harden thick sections.? To slow down the quench requirements and allow thicker sections to be through hardened various other alloying elements can be added, such as Chromium, Vanadium, Cobalt,
Nickel, Manganese etc. ?(Manganese is in virtually all steel anyway, just as a means of mopping up impurities like Phosphorous and Sulphur.? In higher quantities than required to balance the impurities, it leads to extreme work hardening.)
?
In the periodic table of elements, Hydrogen is grouped with the metals.? It is soluble in liquid iron.? For reasons I don't understand, it doesn't cause so much of a problem
in thin mild steel, but in hardenable steel, or even thick mild steel, it comes out of solution during the solidification process and congregates at the grain boundaries, so the grains are not stuck together as well, thereby causing gross lack of strength.
?There is a limit to the % carbon in the steel beyond which you just cannot successfully weld.? Each alloying element is given a carbon equivalent, usually less than 1.? You add all those up in proportion to their % in the composition and add them to the carbon
%.? At a lower figure than the limit, welding can be successful but only if a suitable procedure is devised and followed.? This typically includes the exclusion of hydrogen (moisture, which is why rods are baked for extensive periods), preheating the job for
a period to a specified temperature, maintaining a certain minimum temperature during the welding, maintaining a specified temperature for a significant period after the welding to allow the hydrogen to diffuse out of the job, which it does only slowly, and
finally cooling very slowly.? This is fine if you don't mind losing all the high strength properties as a result of the slow cooling.? Never gone further than this myself, but it may then be possible to reharden the whole job in the normal way.
?
Very sorry, but I feel you're going to have to pay a pro for a procedure if the job is critical, or try some of the above and test it if a few failures are of little consequence.
?There should be info on t'interweb thingy about carbon equivalents and limits.
?
Eddie
?
?
------ Original Message ------
From: ask_derrick=[email protected]
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
Re: Anyone in the Group a Degreed Metallurgist?
Derrick
You have me curious. I have been shooting M1's for many years and never heard of this procedure.
What is the reasoning behind it?
Could you post a picture of what you are doing to the recievers?
Thanks
Erik A
toggle quoted message
Show quoted text
Thank you for the response.
I am mildly familiar with what you discussed on how steels are hardened and the perils of Hydrogen contamination , thru other projects and advisors.
Here is my dilemma, if you can assist, it would be appreciated.
For about 30 years, I have been working on M-1 and M1A rifles. One of the tasks is to weld a recoil lug onto the rear of the receiver. I had a certified welder and he developed the process with the assistance of? the Metallurgy
Department at his day job. He commented on the process several times, but I never wrote it down. He died suddenly, and I am now trying to remember/recreate the process to work with a new welder.
The receivers are carburized 8620, the lugs are 1018, rod is Linde 65, this I know. My memory of the procedure is to tack the lug in two corners, preheat to 800degF, weld the lug in one pass on each side and then water quench.
We had done several hundred receivers, without any failures and I know the process worked. Mostly, I am looking for validation that I remember the process correctly.?
Can you assist?
Thanx and Good Shootin'
Derrick Martin
ask_derrick@...
On Saturday, May 18, 2024 at 02:03:05 AM MST, eddie.draper@... via groups.io <eddie.draper@...> wrote:
I've noted that there is a deafening silence from qualified metallurgists, so as a chartered mechanical engineer, I'll advise what little I know on this subject. ?NO specialist
is going to proffer free advice or any advice that allows you to proceed safely without a.) knowledge of what the steel consists of, b.) the application, including stresses, safety implications etc. and c.) professional indemnity insurance, so what follows
will deliberately be vague while explaining the difficulties against which you are up.
?
The standard advice to welders who want to weld high strength steels is just don't. ?If steel is heat treated, it implies that there was some objective in heat treating it,
such as hardening, and therefore it is at least medium if not high strength.
?
That instruction can be qualified to some extent by someone with a higher level of qualification.
?
Steel that is nominally not hardenable by heat treatment is close to pure iron and is referred to as mild steel. ?This is used for structures, boilers, etc. and the whole point
is that the steel and its weld are ductile.
?
To make it hardenable, various alloying elements are added, the most basic of which is carbon. ?This allows the formation of iron carbide, which is very hard. ?To achieve maximum
hardness, this requires a very quick quench, so you cannot through harden thick sections. ?To slow down the quench requirements and allow thicker sections to be through hardened various other alloying elements can be added, such as Chromium, Vanadium, Cobalt,
Nickel, Manganese etc. ?(Manganese is in virtually all steel anyway, just as a means of mopping up impurities like Phosphorous and Sulphur. ?In higher quantities than required to balance the impurities, it leads to extreme work hardening.)
?
In the periodic table of elements, Hydrogen is grouped with the metals. ?It is soluble in liquid iron. ?For reasons I don't understand, it doesn't cause so much of a problem
in thin mild steel, but in hardenable steel, or even thick mild steel, it comes out of solution during the solidification process and congregates at the grain boundaries, so the grains are not stuck together as well, thereby causing gross lack of strength.
?There is a limit to the % carbon in the steel beyond which you just cannot successfully weld. ?Each alloying element is given a carbon equivalent, usually less than 1. ?You add all those up in proportion to their % in the composition and add them to the carbon
%. ?At a lower figure than the limit, welding can be successful but only if a suitable procedure is devised and followed. ?This typically includes the exclusion of hydrogen (moisture, which is why rods are baked for extensive periods), preheating the job for
a period to a specified temperature, maintaining a certain minimum temperature during the welding, maintaining a specified temperature for a significant period after the welding to allow the hydrogen to diffuse out of the job, which it does only slowly, and
finally cooling very slowly. ?This is fine if you don't mind losing all the high strength properties as a result of the slow cooling. ?Never gone further than this myself, but it may then be possible to reharden the whole job in the normal way.
?
Very sorry, but I feel you're going to have to pay a pro for a procedure if the job is critical, or try some of the above and test it if a few failures are of little consequence.
?There should be info on t'interweb thingy about carbon equivalents and limits.
?
Eddie
?
?
------ Original Message ------
From: ask_derrick@...
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
Re: Anyone in the Group a Degreed Metallurgist?
I think the water quench is problematic, you don't want to create stress. Usually when you do a preheat to weld, you also do a post heat to slow down the cool down.
It's probably to prevent heat migration towards the locking surfaces.
It could be stainless steel rod like 312 or a specialty maintenance rod.
Plenty is unknown, could be high heat input, fast bead? to keep heat input down.
On Sat, May 18, 2024 at 11:24?AM Retired Gunsmith via <ask_derrick= [email protected]> wrote: Thank you for the response. I am mildly familiar with what you discussed on how steels are hardened and the perils of Hydrogen contamination , thru other projects and advisors. Here is my dilemma, if you can assist, it would be appreciated. For about 30 years, I have been working on M-1 and M1A rifles. One of the tasks is to weld a recoil lug onto the rear of the receiver. I had a certified welder and he developed the process with the assistance of? the Metallurgy Department at his day job. He commented on the process several times, but I never wrote it down. He died suddenly, and I am now trying to remember/recreate the process to work with a new welder. The receivers are carburized 8620, the lugs are 1018, rod is Linde 65, this I know. My memory of the procedure is to tack the lug in two corners, preheat to 800degF, weld the lug in one pass on each side and then water quench. We had done several hundred receivers, without any failures and I know the process worked. Mostly, I am looking for validation that I remember the process correctly.? Can you assist?
I've noted that there is a deafening silence from qualified metallurgists, so as a chartered mechanical engineer, I'll advise what little I know on this subject.? NO specialist is going to proffer free advice or any advice that allows you to proceed safely without a.) knowledge of what the steel consists of, b.) the application, including stresses, safety implications etc. and c.) professional indemnity insurance, so what follows will deliberately be vague while explaining the difficulties against which you are up. ? The standard advice to welders who want to weld high strength steels is just don't.? If steel is heat treated, it implies that there was some objective in heat treating it, such as hardening, and therefore it is at least medium if not high strength. ? That instruction can be qualified to some extent by someone with a higher level of qualification. ? Steel that is nominally not hardenable by heat treatment is close to pure iron and is referred to as mild steel.? This is used for structures, boilers, etc. and the whole point is that the steel and its weld are ductile. ? To make it hardenable, various alloying elements are added, the most basic of which is carbon.? This allows the formation of iron carbide, which is very hard.? To achieve maximum hardness, this requires a very quick quench, so you cannot through harden thick sections.? To slow down the quench requirements and allow thicker sections to be through hardened various other alloying elements can be added, such as Chromium, Vanadium, Cobalt, Nickel, Manganese etc. ?(Manganese is in virtually all steel anyway, just as a means of mopping up impurities like Phosphorous and Sulphur.? In higher quantities than required to balance the impurities, it leads to extreme work hardening.) ? In the periodic table of elements, Hydrogen is grouped with the metals.? It is soluble in liquid iron.? For reasons I don't understand, it doesn't cause so much of a problem in thin mild steel, but in hardenable steel, or even thick mild steel, it comes out of solution during the solidification process and congregates at the grain boundaries, so the grains are not stuck together as well, thereby causing gross lack of strength.? There is a limit to the % carbon in the steel beyond which you just cannot successfully weld.? Each alloying element is given a carbon equivalent, usually less than 1.? You add all those up in proportion to their % in the composition and add them to the carbon %.? At a lower figure than the limit, welding can be successful but only if a suitable procedure is devised and followed.? This typically includes the exclusion of hydrogen (moisture, which is why rods are baked for extensive periods), preheating the job for a period to a specified temperature, maintaining a certain minimum temperature during the welding, maintaining a specified temperature for a significant period after the welding to allow the hydrogen to diffuse out of the job, which it does only slowly, and finally cooling very slowly.? This is fine if you don't mind losing all the high strength properties as a result of the slow cooling.? Never gone further than this myself, but it may then be possible to reharden the whole job in the normal way. ? Very sorry, but I feel you're going to have to pay a pro for a procedure if the job is critical, or try some of the above and test it if a few failures are of little consequence.? There should be info on t'interweb thingy about carbon equivalents and limits. ? Eddie
?
? ------ Original Message ------
From: ask_derrick=[email protected]
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
Re: Anyone in the Group a Degreed Metallurgist?
Derrick if ya have not already asked over here on the Practical
Machinist gunsmith portion of the forum Your question should
garner some good info . Free to join & there's? at least a
couple? thousand years of experience there .
good luck
animal
On 5/18/24 8:24 AM, Retired Gunsmith
via groups.io wrote:
toggle quoted message
Show quoted text
Thank you for the response.
I am mildly familiar with
what you discussed on how steels are hardened and the perils
of Hydrogen contamination , thru other projects and
advisors.
Here is my dilemma, if you
can assist, it would be appreciated.
For about 30 years, I have
been working on M-1 and M1A rifles. One of the tasks is to
weld a recoil lug onto the rear of the receiver. I had a
certified welder and he developed the process with the
assistance of? the Metallurgy Department at his day job. He
commented on the process several times, but I never wrote it
down. He died suddenly, and I am now trying to
remember/recreate the process to work with a new welder.
The receivers are
carburized 8620, the lugs are 1018, rod is Linde 65, this I
know. My memory of the procedure is to tack the lug in two
corners, preheat to 800degF, weld the lug in one pass on
each side and then water quench. We had done several hundred
receivers, without any failures and I know the process
worked. Mostly, I am looking for validation that I remember
the process correctly.?
Can you assist?
I've
noted that there is a deafening silence from
qualified metallurgists, so as a chartered
mechanical engineer, I'll advise what little I
know on this subject. ?NO specialist is going to
proffer free advice or any advice that allows you
to proceed safely without a.) knowledge of what
the steel consists of, b.) the application,
including stresses, safety implications etc. and
c.) professional indemnity insurance, so what
follows will deliberately be vague while
explaining the difficulties against which you are
up.
?
The
standard advice to welders who want to weld high
strength steels is just don't. ?If steel is heat
treated, it implies that there was some objective
in heat treating it, such as hardening, and
therefore it is at least medium if not high
strength.
?
That
instruction can be qualified to some extent by
someone with a higher level of qualification.
?
Steel
that is nominally not hardenable by heat treatment
is close to pure iron and is referred to as mild
steel. ?This is used for structures, boilers, etc.
and the whole point is that the steel and its weld
are ductile.
?
To
make it hardenable, various alloying elements are
added, the most basic of which is carbon. ?This
allows the formation of iron carbide, which is
very hard. ?To achieve maximum hardness, this
requires a very quick quench, so you cannot
through harden thick sections. ?To slow down the
quench requirements and allow thicker sections to
be through hardened various other alloying
elements can be added, such as Chromium, Vanadium,
Cobalt, Nickel, Manganese etc. ?(Manganese is in
virtually all steel anyway, just as a means of
mopping up impurities like Phosphorous and
Sulphur. ?In higher quantities than required to
balance the impurities, it leads to extreme work
hardening.)
?
In
the periodic table of elements, Hydrogen is
grouped with the metals. ?It is soluble in liquid
iron. ?For reasons I don't understand, it doesn't
cause so much of a problem in thin mild steel, but
in hardenable steel, or even thick mild steel, it
comes out of solution during the solidification
process and congregates at the grain boundaries,
so the grains are not stuck together as well,
thereby causing gross lack of strength. ?There is
a limit to the % carbon in the steel beyond which
you just cannot successfully weld. ?Each alloying
element is given a carbon equivalent, usually less
than 1. ?You add all those up in proportion to
their % in the composition and add them to the
carbon %. ?At a lower figure than the limit,
welding can be successful but only if a suitable
procedure is devised and followed. ?This typically
includes the exclusion of hydrogen (moisture,
which is why rods are baked for extensive
periods), preheating the job for a period to a
specified temperature, maintaining a certain
minimum temperature during the welding,
maintaining a specified temperature for a
significant period after the welding to allow the
hydrogen to diffuse out of the job, which it does
only slowly, and finally cooling very slowly.
?This is fine if you don't mind losing all the
high strength properties as a result of the slow
cooling. ?Never gone further than this myself, but
it may then be possible to reharden the whole job
in the normal way.
?
Very
sorry, but I feel you're going to have to pay a
pro for a procedure if the job is critical, or try
some of the above and test it if a few failures
are of little consequence. ?There should be info
on t'interweb thingy about carbon equivalents and
limits.
?
Eddie
?
?
------ Original Message ------
From: ask_derrick@...
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a
Degreed Metallurgist?
I am working on a project and need some advice on
welding heat treated materials.
Ask_derrick@...
|
Re: Anyone in the Group a Degreed Metallurgist?
Thank you for the response. I am mildly familiar with what you discussed on how steels are hardened and the perils of Hydrogen contamination , thru other projects and advisors. Here is my dilemma, if you can assist, it would be appreciated. For about 30 years, I have been working on M-1 and M1A rifles. One of the tasks is to weld a recoil lug onto the rear of the receiver. I had a certified welder and he developed the process with the assistance of? the Metallurgy Department at his day job. He commented on the process several times, but I never wrote it down. He died suddenly, and I am now trying to remember/recreate the process to work with a new welder. The receivers are carburized 8620, the lugs are 1018, rod is Linde 65, this I know. My memory of the procedure is to tack the lug in two corners, preheat to 800degF, weld the lug in one pass on each side and then water quench. We had done several hundred receivers, without any failures and I know the process worked. Mostly, I am looking for validation that I remember the process correctly.? Can you assist?
Thanx and Good Shootin'
Derrick Martin
ask_derrick@...
On Saturday, May 18, 2024 at 02:03:05 AM MST, eddie.draper@... via groups.io <eddie.draper@...> wrote:
I've noted that there is a deafening silence from qualified metallurgists, so as a chartered mechanical engineer, I'll advise what little I know on this subject. ?NO specialist is going to proffer free advice or any advice that allows you to proceed safely without a.) knowledge of what the steel consists of, b.) the application, including stresses, safety implications etc. and c.) professional indemnity insurance, so what follows will deliberately be vague while explaining the difficulties against which you are up. ? The standard advice to welders who want to weld high strength steels is just don't. ?If steel is heat treated, it implies that there was some objective in heat treating it, such as hardening, and therefore it is at least medium if not high strength. ? That instruction can be qualified to some extent by someone with a higher level of qualification. ? Steel that is nominally not hardenable by heat treatment is close to pure iron and is referred to as mild steel. ?This is used for structures, boilers, etc. and the whole point is that the steel and its weld are ductile. ? To make it hardenable, various alloying elements are added, the most basic of which is carbon. ?This allows the formation of iron carbide, which is very hard. ?To achieve maximum hardness, this requires a very quick quench, so you cannot through harden thick sections. ?To slow down the quench requirements and allow thicker sections to be through hardened various other alloying elements can be added, such as Chromium, Vanadium, Cobalt, Nickel, Manganese etc. ?(Manganese is in virtually all steel anyway, just as a means of mopping up impurities like Phosphorous and Sulphur. ?In higher quantities than required to balance the impurities, it leads to extreme work hardening.) ? In the periodic table of elements, Hydrogen is grouped with the metals. ?It is soluble in liquid iron. ?For reasons I don't understand, it doesn't cause so much of a problem in thin mild steel, but in hardenable steel, or even thick mild steel, it comes out of solution during the solidification process and congregates at the grain boundaries, so the grains are not stuck together as well, thereby causing gross lack of strength. ?There is a limit to the % carbon in the steel beyond which you just cannot successfully weld. ?Each alloying element is given a carbon equivalent, usually less than 1. ?You add all those up in proportion to their % in the composition and add them to the carbon %. ?At a lower figure than the limit, welding can be successful but only if a suitable procedure is devised and followed. ?This typically includes the exclusion of hydrogen (moisture, which is why rods are baked for extensive periods), preheating the job for a period to a specified temperature, maintaining a certain minimum temperature during the welding, maintaining a specified temperature for a significant period after the welding to allow the hydrogen to diffuse out of the job, which it does only slowly, and finally cooling very slowly. ?This is fine if you don't mind losing all the high strength properties as a result of the slow cooling. ?Never gone further than this myself, but it may then be possible to reharden the whole job in the normal way. ? Very sorry, but I feel you're going to have to pay a pro for a procedure if the job is critical, or try some of the above and test it if a few failures are of little consequence. ?There should be info on t'interweb thingy about carbon equivalents and limits. ? Eddie
?
?
------ Original Message ------
From: ask_derrick@...
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
Re: Anyone in the Group a Degreed Metallurgist?
I've noted that there is a deafening silence from qualified metallurgists, so as a chartered mechanical engineer, I'll advise what little I know on this subject. ?NO specialist is going to proffer free advice or any advice that allows you to proceed safely without a.) knowledge of what the steel consists of, b.) the application, including stresses, safety implications etc. and c.) professional indemnity insurance, so what follows will deliberately be vague while explaining the difficulties against which you are up. ? The standard advice to welders who want to weld high strength steels is just don't. ?If steel is heat treated, it implies that there was some objective in heat treating it, such as hardening, and therefore it is at least medium if not high strength. ? That instruction can be qualified to some extent by someone with a higher level of qualification. ? Steel that is nominally not hardenable by heat treatment is close to pure iron and is referred to as mild steel. ?This is used for structures, boilers, etc. and the whole point is that the steel and its weld are ductile. ? To make it hardenable, various alloying elements are added, the most basic of which is carbon. ?This allows the formation of iron carbide, which is very hard. ?To achieve maximum hardness, this requires a very quick quench, so you cannot through harden thick sections. ?To slow down the quench requirements and allow thicker sections to be through hardened various other alloying elements can be added, such as Chromium, Vanadium, Cobalt, Nickel, Manganese etc. ?(Manganese is in virtually all steel anyway, just as a means of mopping up impurities like Phosphorous and Sulphur. ?In higher quantities than required to balance the impurities, it leads to extreme work hardening.) ? In the periodic table of elements, Hydrogen is grouped with the metals. ?It is soluble in liquid iron. ?For reasons I don't understand, it doesn't cause so much of a problem in thin mild steel, but in hardenable steel, or even thick mild steel, it comes out of solution during the solidification process and congregates at the grain boundaries, so the grains are not stuck together as well, thereby causing gross lack of strength. ?There is a limit to the % carbon in the steel beyond which you just cannot successfully weld. ?Each alloying element is given a carbon equivalent, usually less than 1. ?You add all those up in proportion to their % in the composition and add them to the carbon %. ?At a lower figure than the limit, welding can be successful but only if a suitable procedure is devised and followed. ?This typically includes the exclusion of hydrogen (moisture, which is why rods are baked for extensive periods), preheating the job for a period to a specified temperature, maintaining a certain minimum temperature during the welding, maintaining a specified temperature for a significant period after the welding to allow the hydrogen to diffuse out of the job, which it does only slowly, and finally cooling very slowly. ?This is fine if you don't mind losing all the high strength properties as a result of the slow cooling. ?Never gone further than this myself, but it may then be possible to reharden the whole job in the normal way. ? Very sorry, but I feel you're going to have to pay a pro for a procedure if the job is critical, or try some of the above and test it if a few failures are of little consequence. ?There should be info on t'interweb thingy about carbon equivalents and limits. ? Eddie
?
?
------ Original Message ------
From: ask_derrick@...
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
Re: quick change gearbox questions
Somebody on this list added a rocketronix leadscrew and loved it. I don't remember who, and I am not 100% sure of the spelling, but at 1 am I am not googling anything?
toggle quoted message
Show quoted text
On Wed, Apr 24, 2024 at 09:57 AM, sapark123321 wrote:
Have you considered an electronic leadscrew?
I have considered adding an electric motor with a variable speed, but anything more is beyond my abilities. I have a lot of skills, but electronics is not one of them.
Neil
|
Re: quick change gearbox questions
On Wed, Apr 24, 2024 at 09:57 AM, sapark123321 wrote:
Have you considered an electronic leadscrew?
I have considered adding an electric motor with a variable speed, but anything more is beyond my abilities. I have a lot of skills, but electronics is not one of them. Neil
|
Re: quick change gearbox questions
I have a 4ft 9a with qcgb and it has power? cross feed, like all 9a lathes. I think I Paid $1,100. A qcgb on ebay is $350.?
You can sell your lathe and buy a replacement and out of pocket you might be out less than the price of a gearbox.?
I am not adding the time and effort for the conversion, because I figured you work cheap for yourself.
The original advice was spot on. Sell and upgrade. Keep your tooling.?
toggle quoted message
Show quoted text
On Wed, Apr 24, 2024 at 08:25 AM, Mike Poore wrote:
I can tell you how I handled this situation. I sold my lathe and bought a 9A. The price I got for my old one and the price I paid for the 9A with a GCGB was a lot less than the cost of a GCGB not including the time to fit it. Plus a 9A has auto
crossfeed.
Mine has power crossfeed. I have significant space constraints, so even at 4' this lathe's size is perfect. I do still keep an eye on the local market, and there have been some good ones, but they've been larger ones that I don't have space for. Time fitting
(or even restoring if necessary) is not a concern. I enjoy that sort of work.
Neil
|
Re: quick change gearbox questions
On Wed, Apr 24, 2024 at 08:25 AM, Mike Poore wrote:
I can tell you how I handled this situation. I sold my lathe and bought a 9A. The price I got for my old one and the price I paid for the 9A with a GCGB was a lot less than the cost of a GCGB not including the time to fit it. Plus a 9A has auto crossfeed.
Mine has power crossfeed. I have significant space constraints, so even at 4' this lathe's size is perfect. I do still keep an eye on the local market, and there have been some good ones, but they've been larger ones that I don't have space for. Time fitting (or even restoring if necessary) is not a concern. I enjoy that sort of work. Neil
|
Thanks for the details. Interesting info.
toggle quoted message
Show quoted text
Castings
of all materials contain residual stresses. ?Welded
fabrications contain residual stresses, to the extent that
when conducting stress calculations, you assume that the welds
are already at the yield stress. ?Surface hardening, where a
large temperature difference is induced between the surface
and interior produces what is usually a beneficial residual
compressive stress in the surface. ?Interference fits produce
what are effectively residual stresses. ?
?
Residual
stresses can be overcome prior to machining by either soaking
at a temperature at which creep or yielding occurs, or by
initial over stressing. ?This is why pressure vessels are all
proof tested to a considerably higher pressure than their
working pressure. ?It is to make the highly stressed areas
yield, so that upon removal of the proof pressure, the
residual stress is either much lower or even reversed.
?Residual stresses are also overcome by in service stresses
over a long period. ?I have experience of this occurring and
resulting in fabricated Diesel engine crankcases distorting
and wrecking main bearings or causing leaks around the liner
seat, and axle drive gearboxes on trains distorting to the
extent that bevel gears misalign. ?Incidentally the historic
procedure of leaving castings out in the yard for 6 months
prior to further work is almost entirely ineffective unless
your yard temperature reaches 500C from time to time. ?(500C =
932F, for those still stuck with that system.)
?
For
a tool such as described in this string, I wouldn't worry
about distortion or how soft you can make it. ?Pretty well any
steel will end up soft enough to machine almost as soft as
mild steel if you take it up to temperatures in the high red -
low orange range and cool it slowly enough. ?It is the
re-hardening & tempering I would worry about, as it is
very easy to overdo it and end up with something that either
cracks in service or even at quenching. ?Different alloys want
different hardening & tempering treatments. ?
?
I
rather suspect that a high speed cutter run slow with cutting
oil would last sufficiently to trim down a tool holder. ?Me,
I'd use carbide because I have an indexable cutter, but if I
hadn't, I'd give HSS a try.
?
Eddie,
Chartered Mechanical Engineer, UK
?
------ Original Message ------
From: creswick@...
To: [email protected]
Sent: Monday, April 29th 2024, 03:39
Subject: Re: [SouthBendLathe] Insert Holder Alloy
?
As I understand it, cold formed steels (cold-rolled) have
inherent stresses, as do extruded aluminum/brass/etc... and
as such, they will warp due to material removal alone.
?
Hot rolled do not, or at least to much, much
smaller degree.
?
I would expect that your annealed holders will
not warp a measurable amount due to machining (so you can
likely take all the material off of one side without
worrying about it).
?
I have not gotten around to machining them yet, but I
would expect some warping after hardening. Being that it
is an insert holder, any warping should not matter as
the QCTP holder can be adjusted accordingly. It is hard
to imagine that warping could cause the insert to not
fit, which is the only thing that I see as a problem. I
will chase the retaining screw threads to clear out the
scale.
One point regarding warping: Machining can cause warping
too. I do not know if hardened steel is more or less
likely to warp when machined compared to low carbon (I
would guess less likely), but I have seen low carbon bow
or twist while machining it. I think there is some sort
of stress relief process to prevent it that I have never
investigated.
?
On 4/28/2024 11:20 AM, Andrei via wrote:
?
Mike,
did they warp at all during annealing or subsequent
machining?
?
I
am also curious whether they will warp when you harden
them back.?
?
If
they do, you will have to grind them back to
straight.?
?
They stayed in the oven at 1550 about an hour. I
shut the oven off and left them in overnight to cool
slowly. I did clean the scale off before testing
hardness, but I am still skeptical of it being
softer than 1018. An online source claims 4140
annealed is 12 HRC, so maybe it is plausible.
I have used carbide to cut hardened steel, but it is
not very enjoyable to do on a Clausing 8520 without
coolant. The mill does not have the girth to support
the necessary tool pressure. The risk of breaking
endmills is high. I would rather save my carbide for
when I have no other options.
?
On 4/28/2024 12:16 AM, mike allen via
wrote:
?
Good deal . How long did ya cook them ?
thanks
animal
?
On 4/27/24 8:45 PM, Mike Poore wrote:
?
Just an update in case anyone is interested. I
annealed the tool holders at 1550 F. Before
annealing, they tested at 45 HRC. After
annealing, they tested at 8 HRC. I have read I
should use a B scale tester, but I do not have
one. A scrap piece of 1018 tested at 15 HRC, so
these holders should be easy milling.
?
On 4/25/2024 11:37 AM, Mike Poore via
wrote:
?
I did a search for that number. The indicates
that is the Swedish equivalent to 4340.
Sorry for wasting everyone's time. I hate when
people ask easily answered questions and I am
guilty. I found this that
lists the HT specs for most alloys. 1550F is
within the annealing range of almost every
alloy on the list. 1500F is within the
hardening range for almost all alloys. I will
have to do more research on tempering, but for
an insert holder there should be a wide
tolerance.
?
On 4/25/2024 1:17 AM, Andrei via wrote:
?
Found a reference online to
SS2541 being used for tool bit holders.
Maybe check that.?
The problem is I do not know the alloy. I
guess I will use the 4140 specs.
?
On 4/25/2024 12:59 AM, Andrei via
wrote:
?
That is definitely a great
option. I don't have one so my go-to was
carbide and coolant.youbare in great
shape with the oven
I have a heat treating oven right
next to my mill, so I would rather use
the oven.
?
On 4/24/2024 11:02 PM, Andrei via
wrote:
?
Are short of squirter
bottles or endmills?
Not an option for me.
?
On 4/24/2024 9:43 PM, Andrei
via
wrote:
?
Use a carbide
endmill and coolant. No need to
anneal
Anyone happen to know the
alloy most likely to be used for
carbide insert tool holders? My
guess is 4140. I have four that
I need to mill down to work in
an AXA holder. They test at 45
HRC. Thinking about annealing
them before milling and then
heat treating again, so I would
like specs to use.
?
?
?
?
?
?
?
?
?
|
Castings of all materials contain residual stresses. ?Welded fabrications contain residual stresses, to the extent that when conducting stress calculations, you assume that the welds are already at the yield stress. ?Surface hardening, where a large temperature difference is induced between the surface and interior produces what is usually a beneficial residual compressive stress in the surface. ?Interference fits produce what are effectively residual stresses. ? ? Residual stresses can be overcome prior to machining by either soaking at a temperature at which creep or yielding occurs, or by initial over stressing. ?This is why pressure vessels are all proof tested to a considerably higher pressure than their working pressure. ?It is to make the highly stressed areas yield, so that upon removal of the proof pressure, the residual stress is either much lower or even reversed. ?Residual stresses are also overcome by in service stresses over a long period. ?I have experience of this occurring and resulting in fabricated Diesel engine crankcases distorting and wrecking main bearings or causing leaks around the liner seat, and axle drive gearboxes on trains distorting to the extent that bevel gears misalign. ?Incidentally the historic procedure of leaving castings out in the yard for 6 months prior to further work is almost entirely ineffective unless your yard temperature reaches 500C from time to time. ?(500C = 932F, for those still stuck with that system.) ? For a tool such as described in this string, I wouldn't worry about distortion or how soft you can make it. ?Pretty well any steel will end up soft enough to machine almost as soft as mild steel if you take it up to temperatures in the high red - low orange range and cool it slowly enough. ?It is the re-hardening & tempering I would worry about, as it is very easy to overdo it and end up with something that either cracks in service or even at quenching. ?Different alloys want different hardening & tempering treatments. ? ? I rather suspect that a high speed cutter run slow with cutting oil would last sufficiently to trim down a tool holder. ?Me, I'd use carbide because I have an indexable cutter, but if I hadn't, I'd give HSS a try. ? Eddie, Chartered Mechanical Engineer, UK
?
------ Original Message ------
From: creswick@...
To: [email protected]
Sent: Monday, April 29th 2024, 03:39
Subject: Re: [SouthBendLathe] Insert Holder Alloy
? As I understand it, cold formed steels (cold-rolled) have inherent stresses, as do extruded aluminum/brass/etc... and as such, they will warp due to material removal alone. ? Hot rolled do not, or at least to much, much smaller degree. ? I would expect that your annealed holders will not warp a measurable amount due to machining (so you can likely take all the material off of one side without worrying about it).
?
I have not gotten around to machining them yet, but I would expect some warping after hardening. Being that it is an insert holder, any warping should not matter as the QCTP holder can be adjusted accordingly. It is hard to imagine that warping could cause the insert to not fit, which is the only thing that I see as a problem. I will chase the retaining screw threads to clear out the scale.
One point regarding warping: Machining can cause warping too. I do not know if hardened steel is more or less likely to warp when machined compared to low carbon (I would guess less likely), but I have seen low carbon bow or twist while machining it. I think there is some sort of stress relief process to prevent it that I have never investigated.
? On 4/28/2024 11:20 AM, Andrei via wrote:
? Mike, did they warp at all during annealing or subsequent machining?
?
I am also curious whether they will warp when you harden them back.?
?
If they do, you will have to grind them back to straight.?
?
They stayed in the oven at 1550 about an hour. I shut the oven off and left them in overnight to cool slowly. I did clean the scale off before testing hardness, but I am still skeptical of it being softer than 1018. An online source claims 4140 annealed is 12 HRC, so maybe it is plausible.
I have used carbide to cut hardened steel, but it is not very enjoyable to do on a Clausing 8520 without coolant. The mill does not have the girth to support the necessary tool pressure. The risk of breaking endmills is high. I would rather save my carbide for when I have no other options.
? On 4/28/2024 12:16 AM, mike allen via wrote:
? Good deal . How long did ya cook them ? thanks animal
? On 4/27/24 8:45 PM, Mike Poore wrote:
? Just an update in case anyone is interested. I annealed the tool holders at 1550 F. Before annealing, they tested at 45 HRC. After annealing, they tested at 8 HRC. I have read I should use a B scale tester, but I do not have one. A scrap piece of 1018 tested at 15 HRC, so these holders should be easy milling.
? On 4/25/2024 11:37 AM, Mike Poore via wrote:
? I did a search for that number. The indicates that is the Swedish equivalent to 4340.
Sorry for wasting everyone's time. I hate when people ask easily answered questions and I am guilty. I found this that lists the HT specs for most alloys. 1550F is within the annealing range of almost every alloy on the list. 1500F is within the hardening range for almost all alloys. I will have to do more research on tempering, but for an insert holder there should be a wide tolerance.
? On 4/25/2024 1:17 AM, Andrei via wrote:
? Found a reference online to SS2541 being used for tool bit holders. Maybe check that.?
The problem is I do not know the alloy. I guess I will use the 4140 specs.
? On 4/25/2024 12:59 AM, Andrei via wrote:
? That is definitely a great option. I don't have one so my go-to was carbide and coolant.youbare in great shape with the oven
I have a heat treating oven right next to my mill, so I would rather use the oven.
? On 4/24/2024 11:02 PM, Andrei via wrote:
? Are short of squirter bottles or endmills?
Not an option for me.
? On 4/24/2024 9:43 PM, Andrei via wrote:
? Use a carbide endmill and coolant. No need to anneal
Anyone happen to know the alloy most likely to be used for carbide insert tool holders? My guess is 4140. I have four that I need to mill down to work in an AXA holder. They test at 45 HRC. Thinking about annealing them before milling and then heat treating again, so I would like specs to use.
?
?
?
?
?
?
?
? ?
|
As I understand it, cold formed steels (cold-rolled) have inherent stresses, as do extruded aluminum/brass/etc... and as such, they will warp due to material removal alone.
Hot rolled do not, or at least to much, much smaller degree.
I would expect that your annealed holders will not warp a measurable amount due to machining (so you can likely take all the material off of one side without worrying about it).
I have not gotten around to machining them yet, but I would expect
some warping after hardening. Being that it is an insert holder, any
warping should not matter as the QCTP holder can be adjusted
accordingly. It is hard to imagine that warping could cause the
insert to not fit, which is the only thing that I see as a problem.
I will chase the retaining screw threads to clear out the scale.
One point regarding warping: Machining can cause warping too. I do
not know if hardened steel is more or less likely to warp when
machined compared to low carbon (I would guess less likely), but I
have seen low carbon bow or twist while machining it. I think there
is some sort of stress relief process to prevent it that I have
never investigated.
On 4/28/2024 11:20 AM, Andrei via
wrote:
Mike, did they warp at all during annealing or subsequent
machining?
I am also curious whether they will warp when you harden them
back.?
If they do, you will have to grind them back to straight.?
They stayed in the oven at 1550 about an hour. I shut the
oven off and left them in overnight to cool slowly. I did clean
the scale off before testing hardness, but I am still skeptical
of it being softer than 1018. An online source claims 4140
annealed is 12 HRC, so maybe it is plausible.
I have used carbide to cut hardened steel, but it is not very
enjoyable to do on a Clausing 8520 without coolant. The mill
does not have the girth to support the necessary tool pressure.
The risk of breaking endmills is high. I would rather save my
carbide for when I have no other options.
On 4/28/2024 12:16 AM, mike allen
via wrote:
Good deal . How long did ya cook them ?
thanks
animal
On 4/27/24 8:45 PM, Mike Poore
wrote:
Just an update in case anyone is
interested. I annealed the tool holders at 1550 F. Before
annealing, they tested at 45 HRC. After annealing, they
tested at 8 HRC. I have read I should use a B scale tester,
but I do not have one. A scrap piece of 1018 tested at 15
HRC, so these holders should be easy milling.
On 4/25/2024 11:37 AM, Mike
Poore via wrote:
I did a search for that number. The
indicates that is the Swedish equivalent to
4340.
Sorry for wasting everyone's time. I hate when people ask
easily answered questions and I am guilty. I found this
that lists the HT specs for most alloys.
1550F is within the annealing range of almost every alloy
on the list. 1500F is within the hardening range for
almost all alloys. I will have to do more research on
tempering, but for an insert holder there should be a wide
tolerance.
On 4/25/2024 1:17 AM,
Andrei via wrote:
Found a reference online to SS2541 being
used for tool bit holders. Maybe check that.?
The problem is I do not know the alloy. I guess I
will use the 4140 specs.
On 4/25/2024 12:59
AM, Andrei via wrote:
That is definitely a great option. I
don't have one so my go-to was carbide and
coolant.youbare in great shape with the oven
I have a heat treating oven right next to my
mill, so I would rather use the oven.
On 4/24/2024
11:02 PM, Andrei via wrote:
Are short of squirter bottles or
endmills?
Not an option for me.
On
4/24/2024 9:43 PM, Andrei via
wrote:
Use a carbide endmill and
coolant. No need to anneal
Anyone happen to know the alloy most
likely to be used for carbide insert tool
holders? My guess is 4140. I have four
that I need to mill down to work in an AXA
holder. They test at 45 HRC. Thinking
about annealing them before milling and
then heat treating again, so I would like
specs to use.
|
I have not gotten around to machining them yet, but I would expect
some warping after hardening. Being that it is an insert holder, any
warping should not matter as the QCTP holder can be adjusted
accordingly. It is hard to imagine that warping could cause the
insert to not fit, which is the only thing that I see as a problem.
I will chase the retaining screw threads to clear out the scale.
One point regarding warping: Machining can cause warping too. I do
not know if hardened steel is more or less likely to warp when
machined compared to low carbon (I would guess less likely), but I
have seen low carbon bow or twist while machining it. I think there
is some sort of stress relief process to prevent it that I have
never investigated.
On 4/28/2024 11:20 AM, Andrei via
groups.io wrote:
toggle quoted message
Show quoted text
Mike, did they warp at all during annealing or subsequent
machining?
I am also curious whether they will warp when you harden them
back.?
If they do, you will have to grind them back to straight.?
They stayed in the oven at 1550 about an hour. I shut the
oven off and left them in overnight to cool slowly. I did clean
the scale off before testing hardness, but I am still skeptical
of it being softer than 1018. An online source claims 4140
annealed is 12 HRC, so maybe it is plausible.
I have used carbide to cut hardened steel, but it is not very
enjoyable to do on a Clausing 8520 without coolant. The mill
does not have the girth to support the necessary tool pressure.
The risk of breaking endmills is high. I would rather save my
carbide for when I have no other options.
On 4/28/2024 12:16 AM, mike allen
via groups.io wrote:
Good deal . How long did ya cook them ?
thanks
animal
On 4/27/24 8:45 PM, Mike Poore
wrote:
Just an update in case anyone is
interested. I annealed the tool holders at 1550 F. Before
annealing, they tested at 45 HRC. After annealing, they
tested at 8 HRC. I have read I should use a B scale tester,
but I do not have one. A scrap piece of 1018 tested at 15
HRC, so these holders should be easy milling.
On 4/25/2024 11:37 AM, Mike
Poore via groups.io wrote:
I did a search for that number. The
indicates that is the Swedish equivalent to
4340.
Sorry for wasting everyone's time. I hate when people ask
easily answered questions and I am guilty. I found this
that lists the HT specs for most alloys.
1550F is within the annealing range of almost every alloy
on the list. 1500F is within the hardening range for
almost all alloys. I will have to do more research on
tempering, but for an insert holder there should be a wide
tolerance.
On 4/25/2024 1:17 AM,
Andrei via groups.io wrote:
Found a reference online to SS2541 being
used for tool bit holders. Maybe check that.?
The problem is I do not know the alloy. I guess I
will use the 4140 specs.
On 4/25/2024 12:59
AM, Andrei via groups.io wrote:
That is definitely a great option. I
don't have one so my go-to was carbide and
coolant.youbare in great shape with the oven
I have a heat treating oven right next to my
mill, so I would rather use the oven.
On 4/24/2024
11:02 PM, Andrei via groups.io wrote:
Are short of squirter bottles or
endmills?
Not an option for me.
On
4/24/2024 9:43 PM, Andrei via groups.io
wrote:
Use a carbide endmill and
coolant. No need to anneal
Anyone happen to know the alloy most
likely to be used for carbide insert tool
holders? My guess is 4140. I have four
that I need to mill down to work in an AXA
holder. They test at 45 HRC. Thinking
about annealing them before milling and
then heat treating again, so I would like
specs to use.
|
Mike, did they warp at all during annealing or subsequent machining?
I am also curious whether they will warp when you harden them back.?
If they do, you will have to grind them back to straight.?
toggle quoted message
Show quoted text
They stayed in the oven at 1550 about an hour. I shut the oven off and left them in overnight to cool slowly. I did clean the scale off before testing hardness, but I am still skeptical of it being softer than 1018. An online source claims 4140 annealed
is 12 HRC, so maybe it is plausible.
I have used carbide to cut hardened steel, but it is not very enjoyable to do on a Clausing 8520 without coolant. The mill does not have the girth to support the necessary tool pressure. The risk of breaking endmills is high. I would rather save my carbide
for when I have no other options.
On 4/28/2024 12:16 AM, mike allen via groups.io wrote:
Good deal . How long did ya cook them ?
thanks
animal
On 4/27/24 8:45 PM, Mike Poore wrote:
Just an update in case anyone is interested. I annealed the tool holders at 1550 F. Before annealing, they tested at 45 HRC. After annealing, they tested at 8 HRC. I have read I should use a B scale tester, but I do not have one. A scrap
piece of 1018 tested at 15 HRC, so these holders should be easy milling.
On 4/25/2024 11:37 AM, Mike Poore via groups.io wrote:
I did a search for that number. The indicates that is the Swedish equivalent to 4340.
Sorry for wasting everyone's time. I hate when people ask easily answered questions and I am guilty. I found this
that lists the HT specs for most alloys. 1550F is within the annealing range of almost every alloy on the list. 1500F is within the hardening range for almost all alloys. I will have to do more research on tempering, but for an insert holder there
should be a wide tolerance.
On 4/25/2024 1:17 AM, Andrei via groups.io wrote:
Found a reference online to SS2541 being used for tool bit holders. Maybe check that.?
The problem is I do not know the alloy. I guess I will use the 4140 specs.
On 4/25/2024 12:59 AM, Andrei via groups.io wrote:
That is definitely a great option. I don't have one so my go-to was carbide and coolant.youbare in great shape with the oven
I have a heat treating oven right next to my mill, so I would rather use the oven.
On 4/24/2024 11:02 PM, Andrei via groups.io wrote:
Are short of squirter bottles or endmills?
Not an option for me.
On 4/24/2024 9:43 PM, Andrei via groups.io wrote:
Use a carbide endmill and coolant. No need to anneal
Anyone happen to know the alloy most likely to be used for carbide insert tool holders? My guess is 4140. I have four that I need to mill down to work in an AXA holder. They test at 45 HRC. Thinking about annealing them before milling and then heat treating
again, so I would like specs to use.
|
They stayed in the oven at 1550 about an hour. I shut the oven off
and left them in overnight to cool slowly. I did clean the scale off
before testing hardness, but I am still skeptical of it being softer
than 1018. An online source claims 4140 annealed is 12 HRC, so maybe
it is plausible.
I have used carbide to cut hardened steel, but it is not very
enjoyable to do on a Clausing 8520 without coolant. The mill does
not have the girth to support the necessary tool pressure. The risk
of breaking endmills is high. I would rather save my carbide for
when I have no other options.
On 4/28/2024 12:16 AM, mike allen via
groups.io wrote:
toggle quoted message
Show quoted text
Good deal . How long did ya cook them ?
thanks
animal
On 4/27/24 8:45 PM, Mike Poore wrote:
Just an update in case anyone is interested. I annealed the tool
holders at 1550 F. Before annealing, they tested at 45 HRC.
After annealing, they tested at 8 HRC. I have read I should use
a B scale tester, but I do not have one. A scrap piece of 1018
tested at 15 HRC, so these holders should be easy milling.
On 4/25/2024 11:37 AM, Mike Poore
via groups.io wrote:
I did a search for that number. The indicates that is the
Swedish equivalent to 4340.
Sorry for wasting everyone's time. I hate when people ask
easily answered questions and I am guilty. I found this that lists the HT specs
for most alloys. 1550F is within the annealing range of almost
every alloy on the list. 1500F is within the hardening range
for almost all alloys. I will have to do more research on
tempering, but for an insert holder there should be a wide
tolerance.
On 4/25/2024 1:17 AM, Andrei via
groups.io wrote:
Found a reference online to SS2541 being
used for tool bit holders. Maybe check that.?
The problem is I do not know the alloy. I guess I will
use the 4140 specs.
On 4/25/2024 12:59 AM,
Andrei via groups.io wrote:
That is definitely a great option. I
don't have one so my go-to was carbide and
coolant.youbare in great shape with the oven
I have a heat treating oven right next to my mill,
so I would rather use the oven.
On 4/24/2024 11:02
PM, Andrei via groups.io wrote:
Are short of squirter bottles or
endmills?
Not an option for me.
On 4/24/2024
9:43 PM, Andrei via groups.io wrote:
Use a carbide endmill and
coolant. No need to anneal
Anyone happen to know the alloy most likely
to be used for carbide insert tool holders? My
guess is 4140. I have four that I need to mill
down to work in an AXA holder. They test at 45
HRC. Thinking about annealing them before
milling and then heat treating again, so I
would like specs to use.
|
I did not have any problems machining my insert holders, I did nothing to them and used a carbide cutter.
Gary
|
Good deal . How long did ya cook them ?
thanks
animal
On 4/27/24 8:45 PM, Mike Poore wrote:
toggle quoted message
Show quoted text
Just an update in case anyone is interested. I annealed the tool
holders at 1550 F. Before annealing, they tested at 45 HRC. After
annealing, they tested at 8 HRC. I have read I should use a B
scale tester, but I do not have one. A scrap piece of 1018 tested
at 15 HRC, so these holders should be easy milling.
On 4/25/2024 11:37 AM, Mike Poore via
groups.io wrote:
I did a search for that number. The indicates that is the Swedish
equivalent to 4340.
Sorry for wasting everyone's time. I hate when people ask easily
answered questions and I am guilty. I found this that lists the HT specs
for most alloys. 1550F is within the annealing range of almost
every alloy on the list. 1500F is within the hardening range for
almost all alloys. I will have to do more research on tempering,
but for an insert holder there should be a wide tolerance.
On 4/25/2024 1:17 AM, Andrei via
groups.io wrote:
Found a reference online to SS2541 being used
for tool bit holders. Maybe check that.?
The problem is I do not know the alloy. I guess I will
use the 4140 specs.
On 4/25/2024 12:59 AM, Andrei
via groups.io wrote:
That is definitely a great option. I don't
have one so my go-to was carbide and coolant.youbare in
great shape with the oven
I have a heat treating oven right next to my mill, so
I would rather use the oven.
On 4/24/2024 11:02 PM,
Andrei via groups.io wrote:
Are short of squirter bottles or
endmills?
Not an option for me.
On 4/24/2024 9:43
PM, Andrei via groups.io wrote:
Use a carbide endmill and coolant.
No need to anneal
Anyone happen to know the alloy most likely
to be used for carbide insert tool holders? My
guess is 4140. I have four that I need to mill
down to work in an AXA holder. They test at 45
HRC. Thinking about annealing them before
milling and then heat treating again, so I would
like specs to use.
|
Nick Andrews
Neil Hitze