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Hi can someone tell me what thread the screws are that hold the back panel on? HP8656. I am assuming they are 5/32 as 3mm and 4mm metric are either too small or too big. or wrong thread
Are the UNF , UNC or something else? imperial thread screws are not common in Australia, and I have lost all teh screws out of the back of my sig gen.
?I think the ones i ordered were bsw and of course don't fit
?
Wayne?
VK2WDE
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It is likely that they are imperial 6-32 pan head pozi-drive ( looks like a Phillips head, but slightly different.) The outside dia. of a 6-32 screw is about 0.138 inch (~3.5mm) and 32 threads per inch.
On Mon, Mar 17, 2025 at 12:25?AM Wayne Eckert via <Wayne.Eckert= [email protected]> wrote: Hi can someone tell me what thread the screws are that hold the back panel on? HP8656. I am assuming they are 5/32 as 3mm and 4mm metric are either too small or too big. or wrong thread
Are the UNF , UNC or something else? imperial thread screws are not common in Australia, and I have lost all teh screws out of the back of my sig gen.
?I think the ones i ordered were bsw and of course don't fit
?
Wayne?
VK2WDE
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On 2025-03-17 12:25 AM, Wayne Eckert via groups.io wrote: Hi can someone tell me what thread the screws are that hold the back panel on? HP8656. I am assuming they are 5/32 as 3mm and 4mm metric are either too small or too big. or wrong thread There's also a 3.5mm standard thread, used on IEEE-488 connectors, that might be a possibility. Steve Hendrix
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p. 6-36. 4 * MP101, 6-32.
G?ran
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I went to a hardware specialty store with one of the Torx screws from the 8643. They said it was not a metric diameter. Nor was it 32 threads per inch, a US "coarse" thread. They said it look like it was a US? #6-40, an uncommon but US-standard "fine thread". Today I bought a baggie with 20 and.......it appears to be close to the right diameter but it is not 40 threads per inch.
I have not figured out what the thread is, but it is NOT a US fine threaded, 6-40.
Bill
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On 3/17/2025 3:54 AM, Steve Hendrix wrote: On 2025-03-17 12:25 AM, Wayne Eckert via groups.io wrote:
Hi can someone tell me what thread the screws are that hold the back panel on? HP8656. I am assuming they are 5/32 as 3mm and 4mm metric are either too small or too big. or wrong thread There's also a 3.5mm standard thread, used on IEEE-488 connectors, that might be a possibility.
Steve Hendrix
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Asian mystery screws that are almost imperial measurements...
Jim
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I went to a hardware specialty store with one of the Torx screws from
the 8643. They said it was not a metric diameter. Nor was it 32 threads
per inch, a US "coarse" thread. They said it look like it was a US?
#6-40, an uncommon but US-standard "fine thread". Today I bought a
baggie with 20 and.......it appears to be close to the right diameter
but it is not 40 threads per inch.
I have not figured out what the thread is, but it is NOT a US fine
threaded, 6-40.
Bill
On 3/17/2025 3:54 AM, Steve Hendrix wrote:
> On 2025-03-17 12:25 AM, Wayne Eckert via groups.io wrote:
>> Hi can someone tell me what thread the screws are that hold the back
>> panel on? HP8656. I am assuming they are 5/32 as 3mm and 4mm metric
>> are either too small or too big. or wrong thread
>
> There's also a 3.5mm standard thread, used on IEEE-488 connectors,
> that might be a possibility.
>
> Steve Hendrix
>
>
>
>
>
>
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Maybe I have the same problem as the 8656: the cover screws for the 8643 is NOT 6-32 (USA, national coarse), nor is it 6-40 (USA, national fine). The diameter is very close to USA #6, a finer thread than 32 threads per inch. It has to be some metric size that the local specialty guy did not recognize.
Thank you Goran for the idea of looking at the parts list. I will try to find an 8643 manual on line somewhere and see what it says.
Bill
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On 3/17/2025 5:17 AM, G?ran Krusell via groups.io wrote: p. 6-36. 4 * MP101, 6-32.
G?ran
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If the unit is English then the screws are 4-40, 6-32, and 8-32.
If the unit is metric then the screws are 2.5 mm, 3.5 mm, and 4.0 mm
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From my long ago youth futzing around in a tool and die shop, I recall, there is also a (rarely found) 5-40 ANSI thread
Sure enough:
-Dale
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On Mar 17, 2025, at 19:14, Don Bitters via groups.io <donbitters@...> wrote:
If the unit is English then the screws are 4-40, 6-32, and 8-32.
If the unit is metric then the screws are 2.5 mm, 3.5 mm, and 4.0 mm
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M3.5x.6
搁别苍é别
On 3/17/25 10:57 AM, Bill Carver via
groups.io wrote:
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Maybe I
have the same problem as the 8656: the cover screws for the 8643
is NOT 6-32 (USA, national coarse), nor is it 6-40 (USA, national
fine). The diameter is very close to USA #6, a finer thread than
32 threads per inch. It has to be some metric size that the local
specialty guy did not recognize.
Thank you Goran for the idea of looking at the parts list. I will
try to find an 8643 manual on line somewhere and see what it says.
Bill
On 3/17/2025 5:17 AM, G?ran Krusell via groups.io wrote:
p. 6-36. 4 * MP101, 6-32.
G?ran
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UNOFFICIAL
?
I misread the parts list and thought it was 5/32. 3MM is too small , 4mm is too big, 5/32 BSW doesn't screw in
?
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Wayne Eckert BEng
Observing Operations Hub Sydney
M:0409986684
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T: 02 92961668
Unit 9 ?111 Moore Street
Leichhardt NSW 2040
wayne.eckert@... |
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?
?
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From: [email protected] <[email protected]>
On Behalf Of 搁别苍é别 via groups.io
Sent: Tuesday, 18 March 2025 1:59 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Threads for screws on 8656 Siggen
?
M3.5x.6
搁别苍é别
On 3/17/25 10:57 AM, Bill Carver via groups.io wrote:
Maybe I have the same problem as the 8656: the cover screws for the 8643 is NOT 6-32 (USA, national coarse), nor is it 6-40 (USA, national fine). The diameter is very close to USA #6, a finer thread than 32 threads per inch. It has to be
some metric size that the local specialty guy did not recognize.
Thank you Goran for the idea of looking at the parts list. I will try to find an 8643 manual on line somewhere and see what it says.
Bill
On 3/17/2025 5:17 AM, G?ran Krusell via groups.io wrote:
p. 6-36. 4 * MP101, 6-32.
G?ran
?
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If it's indeed M3.5 x 0.6, it's the same size as the hardware used on the recent HP-IB connectors, the ones with black screws (early HP-IB connectors used uncolored stainless steel 6-32 American hardware). You can check for compatibility with the screws on an HP-IB connector.
This is indeed a metric size, but a very unusual one which is not easily found, even here in Europe. Very few hardware vendors have them, one of them is here :
(no affiliation with them).
I hope this helps !
Joel Setton
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Hi all
The threads you are looking for are M3.5, this is a little used thread except in the UK where it is used by electricians to hold switch face plates in place, it is actually very close to 4BA which were the original screws used..
HP used this thread in place of 6-32 when NATO and the US military required all threads to be ISO Metric. The tapping hole diameter is almost the same for 6-32 and M3.5, it is predominately used in case work only, particularly castings.
Hope this helps
G Edmonds
On Tuesday 18 March 2025 at 10:07:20 GMT, Joel Setton via groups.io <setton@...> wrote:
If it's indeed M3.5 x 0.6, it's the same size as the hardware used on the recent HP-IB connectors, the ones with black screws (early HP-IB connectors used uncolored stainless steel 6-32 American hardware). You can check for compatibility with the screws on an HP-IB connector.
This is indeed a metric size, but a very unusual one which is not easily found, even here in Europe. Very few hardware vendors have them, one of them is here : (no affiliation with them). I hope this helps ! Joel Setton
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Amazon lists a significant number of different M3.5-0.6 screws. Some are cheap at 9-13 cents each, some are expensive tamper resistant heads closer to a dollar each than pennies, and some have carton quantities of multiple thousands of pieces.
?
But there are some where a package is under 10 USD.
Mouser even has a few.
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For what it's worth, here in the U.S. McMaster-Carr has M3.5 x 0.6 pitch screws?
?
-Pat
?
> ------ Original Message ------
> From: setton@...
> To: [email protected]
> Sent: Tuesday, March 18th 2025, 06:07 AM
> Subject: Re: [HP-Agilent-Keysight-equipment] Threads for screws on 8656 Siggen
? If it's indeed M3.5 x 0.6, it's the same size as the hardware used on the recent HP-IB connectors, the ones with black screws (early HP-IB connectors used uncolored stainless steel 6-32 American hardware). You can check for compatibility with the screws on an HP-IB connector.
? This is indeed a metric size, but a very unusual one which is not easily found, even here in Europe. Very few hardware vendors have them, one of them is here : (no affiliation with them). I hope this helps ! Joel Setton
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Apparently the first tilde split the link (at least as it came to me in the message) - copy and paste the entire line to get directly to the M3.5 x 0.6 screws. -Pat
?
> ------ Original Message ------
> From: pbmanning@...
> To: [email protected]
> Sent: Tuesday, March 18th 2025, 12:21 PM
> Subject: Re: [HP-Agilent-Keysight-equipment] Threads for screws on 8656 Siggen
? For what it's worth, here in the U.S. McMaster-Carr has M3.5 x 0.6 pitch screws?
?
-Pat
? > ------ Original Message ------
> From: setton@...
> To: [email protected]
> Sent: Tuesday, March 18th 2025, 06:07 AM
> Subject: Re: [HP-Agilent-Keysight-equipment] Threads for screws on 8656 Siggen
? If it's indeed M3.5 x 0.6, it's the same size as the hardware used on the recent HP-IB connectors, the ones with black screws (early HP-IB connectors used uncolored stainless steel 6-32 American hardware). You can check for compatibility with the screws on an HP-IB connector.
? This is indeed a metric size, but a very unusual one which is not easily found, even here in Europe. Very few hardware vendors have them, one of them is here : (no affiliation with them). I hope this helps ! Joel Setton
|
here is a thread
comparison and pitch charts for future info
搁别苍é别
On 3/18/25 9:21 AM, Cubdriver via
groups.io wrote:
toggle quoted message
Show quoted text
For what it's
worth, here in the U.S. McMaster-Carr has M3.5 x 0.6 pitch
screws?
?
-Pat
?
> ------ Original Message ------
> From: setton@...
> To: [email protected]
> Sent: Tuesday, March 18th 2025, 06:07 AM
> Subject: Re: [HP-Agilent-Keysight-equipment] Threads for
screws on 8656 Siggen
?
If it's indeed M3.5 x 0.6, it's the same size as the
hardware used on the recent HP-IB connectors, the ones with
black screws (early HP-IB connectors used uncolored stainless
steel 6-32 American hardware). You can check for compatibility
with the screws on an HP-IB connector.
?
This is indeed a metric size, but a very unusual one which
is not easily found, even here in Europe. Very few hardware
vendors have them, one of them is here :
(no affiliation with them).
I hope this helps !
Joel Setton
|
I have the screw from an HP8664A, which I assume will be similar. Pan head, torx drive.
I checked it with various thread gauges, and if you're not looking closely (i.e. under a magnifier or microscope) you'd be inclined to say it's 42TPI, but under the microscope I can see 42TPI isn't correct - the screw gets every so slightly out of sync with the thread gauge over the length of the screw.
Checking the metric gauges, it meshes exactly with 0.6mm, so 搁别苍é别 is correct - it must be 3.5mm 0.6mm/thread
You should get yourself a set of thread gauges - they come in handy for all sorts of stuff, and they're not that expensive. $10 gets you one with both metric and imperial. They tend to have them in the hardware store if you want to go to a local brick and mortar store to get them, but they can be hard to find - usually tucked away in a dusty corner of the hand tool section somewhere.
Link here as an example, not an endorsement of this particular gauge (though the ones I have are very similar, but came with a tap and die set, and I got another set when I bought 'fishtail' gauges for threading on the lathe with a single point threading tool):
here is a thread
comparison and pitch charts for future info
搁别苍é别
On 3/18/25 9:21 AM, Cubdriver via
wrote:
For what it's
worth, here in the U.S. McMaster-Carr has M3.5 x 0.6 pitch
screws?
?
-Pat
?
> ------ Original Message ------
> From: setton@...
> To: [email protected]
> Sent: Tuesday, March 18th 2025, 06:07 AM
> Subject: Re: [HP-Agilent-Keysight-equipment] Threads for
screws on 8656 Siggen
?
If it's indeed M3.5 x 0.6, it's the same size as the
hardware used on the recent HP-IB connectors, the ones with
black screws (early HP-IB connectors used uncolored stainless
steel 6-32 American hardware). You can check for compatibility
with the screws on an HP-IB connector.
?
This is indeed a metric size, but a very unusual one which
is not easily found, even here in Europe. Very few hardware
vendors have them, one of them is here :
(no affiliation with them).
I hope this helps !
Joel Setton
|
I just noticed that gauge I linked to is 60 degree metric, and 55 degree imperial (whitworth), so that's not a good "covers both common systems" thread gauge - that said, I did run into stupid Whitworth threads on some hydraulic fittings in the last few months, so it's ideal to have all 3 gauges on hand - 60 degree metric, 60 degree imperial, and 55 degree whitworth - you never know what crazy thread you might run into randomly.
I have the screw from an HP8664A, which I assume will be similar. Pan head, torx drive.
I checked it with various thread gauges, and if you're not looking closely (i.e. under a magnifier or microscope) you'd be inclined to say it's 42TPI, but under the microscope I can see 42TPI isn't correct - the screw gets every so slightly out of sync with the thread gauge over the length of the screw.
Checking the metric gauges, it meshes exactly with 0.6mm, so 搁别苍é别 is correct - it must be 3.5mm 0.6mm/thread
You should get yourself a set of thread gauges - they come in handy for all sorts of stuff, and they're not that expensive. $10 gets you one with both metric and imperial. They tend to have them in the hardware store if you want to go to a local brick and mortar store to get them, but they can be hard to find - usually tucked away in a dusty corner of the hand tool section somewhere.
Link here as an example, not an endorsement of this particular gauge (though the ones I have are very similar, but came with a tap and die set, and I got another set when I bought 'fishtail' gauges for threading on the lathe with a single point threading tool):
here is a thread
comparison and pitch charts for future info
搁别苍é别
On 3/18/25 9:21 AM, Cubdriver via
wrote:
For what it's
worth, here in the U.S. McMaster-Carr has M3.5 x 0.6 pitch
screws?
?
-Pat
?
> ------ Original Message ------
> From: setton@...
> To: [email protected]
> Sent: Tuesday, March 18th 2025, 06:07 AM
> Subject: Re: [HP-Agilent-Keysight-equipment] Threads for
screws on 8656 Siggen
?
If it's indeed M3.5 x 0.6, it's the same size as the
hardware used on the recent HP-IB connectors, the ones with
black screws (early HP-IB connectors used uncolored stainless
steel 6-32 American hardware). You can check for compatibility
with the screws on an HP-IB connector.
?
This is indeed a metric size, but a very unusual one which
is not easily found, even here in Europe. Very few hardware
vendors have them, one of them is here :
(no affiliation with them).
I hope this helps !
Joel Setton
|
On Mon, Mar 17, 2025 at 09:59 PM, 搁别苍é别 wrote:
A #6 screw is almost exactly 3.5 mm diameter.
?
0.6 pitch comes out to just over 42 per inch.
?
0.7 pitch comes out to just over 36 per inch, but M3.5 x 0.7 does not appear to be a real option.
--
Jim Adney
Madison, WI USA
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G?ran Krusell
Bill Carver
Cubdriver