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Re: Broken Tap
开云体育As others have said, you need a tapping guide. I prefer a spring loaded tapping center, Fisher makes a good one:Then you need to clamp the part, drill the hole and while you are still over center, use the spring loaded tapping guid and run your tap. You want to get a two or three flute spiral point gun tap for 1/2-13 thru holes. You don’t have enough HP or arms long enough to roll tap (thread form) in 1/2-13 and then there is the whole issue of minor diameter, which when thread forming has to be spot on, like within .001”, not whatever drill size is close. It wil help a lot if you look at your thread chart and drill the next size up on the minor diameter, with that corse of a thread, at least .010 over size would be no issue. Last tip is to use Moly-Dee thread cutting fluid on steel, it stinks, it stains everything green, fingers included, but it will lower your torque requirements by probably close to half. In production we used to mix 510 Drawing oil, picture a thick honey consistency, with Moly-Dee and called it Gorilla Snot. The thick oil made it stick to the tap better and the moly-dee made it cut. I hate to think about how many 3/4-16 threads I cut in 347 Stainless Steel by hand when I was a kid… oh, and the tap handle had arms on it 12”-16" long on each side so you could get the leverage you needed. The tap handle below is a 16” long Starrett…. it’ll cost you unless you can find one used.
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Re: Sliding Table Saw Felder K700 S - Minnesota
Don't these usually list for close to $15k new? Even though this certainly isnt "mint condition" it might be a good deal.? Does anyone know what the going price is from Felder? On Mon, Dec 14, 2020 at 8:27 AM Chris Perren <cperren@...> wrote:
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Re: Broken Tap
Most taps have a countersink on the end so that you can use a DP for alignment when hand tapping:
Use thread cutting fluid, not 3-in-1 oil.? It makes a big difference. Spiral taps are more expensive, but require less torque.? ? ? Chamfering the hole will ease starting. Get combo drill/taps: Then you can do it in one step on your drill press.? And if you do drill holes separately, still use the drill/tap in your hand tapper because drill part makes the tap self-aligning and you don't need to fuss with guides or eyeballing a square (obviously only applies to thru holes) ? ? |
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Re: Broken Tap
Cliff Rohrabacher, Esq.
开云体育oh? and if ya really? want to just drill a hole and tap it? Get a
free machining steel.? I like? any of the Leadloy? free machining
steels Ya can braise 'em but ya? can not weld? them and they cut
like Buttah.? When tapped it's almost like they are self lubricating.?? you can
use 12L14.? The stuff is almost like machining Acetal plastic On 12/13/20 7:55 PM, imranindiana via
groups.io wrote:
is anyone familiar with accusize industrial tools? it is a canadian co out of toronto. i recently purchased two tap & drill sets metric and SAE. i went with them because they offered HSS at reasonable price. |
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Re: Broken Tap that's not a manufacturing defect that is a purchasing mistake
Cliff Rohrabacher, Esq.
开云体育You bought the wrong tap.? Cheap taps are? worthless, as you
discovered. Taps? worth buying : Balax for thread forming.? OSG and Emuge for cutting. I? don't know of another company making? taps that are worth a damn.?? For hand tapping? Use either thread forming taps or Two Flute Gun Taps. For bl;inf holes use Spiral taps? they are usually three flutes There is? absolutely? no circumstance in which I would bother
with a four flute tap. They are weak as hell? - - which you just
found out.? Use a high sulfur? cutting oil? or a specialty? tapping fluid? like TapFree there are many good tapping fluids? In malleable metals like Steel and Aluminum I prefer to form the threads? instead of cutting.? If you are jobber you need to check the print and see if they are acceptable. In high hardened steel? I prefer to send it out to an EDM shop
but I can tap? pre hard 4140 and 4150? if the hardness is? 48 RC?
and not more. 1018 is about the same as A36.? it is a Weee skosh more? machinable? but not worth the money? unless you are running lots of it and need the? better finish.? It takes more skill to get a great finish on A-36.
Cold Rolled is? OK? if you plan on doing little more? than
drilling and tapping? but if you plan on machining the mill
surfaces then? stay away from the stuff.?? The stresses in the
surfaces from the? rolling mil will cause the metal to form banana
shapes as you remove stock from one side or the other and you can
be chasing your tail trying to get it to lie flat? all day. On 12/13/20 7:55 PM, imranindiana via
groups.io wrote:
is anyone familiar with accusize industrial tools? it is a canadian co out of toronto. i recently purchased two tap & drill sets metric and SAE. i went with them because they offered HSS at reasonable price. |
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Re: Broken Tap
Sorry to go off topic but I am unfamiliar with the Survival Guide. Is this only for a Felder slider or would it be worthwhile for all? Thanks.
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Imran, it really helps to make a tap guide. ? See pages 222-223 in your Survival Guide. ? |
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Re: Broken Tap
开云体育JP, that is a great idea. i will see if i can adapt my gearwrench ratcheting handle to mount in the DP. Imran On Dec 14, 2020, at 8:42 AM, Jerry P <Jerry-Pac-Man@...> wrote:
?I use a hand tap wrench mounted in a drill press. After I drill the hole I mount the tap wrench.? It is not powered just a guide.? Also, tapping fluid is used. -- Jerry P Life is what happens to you when you're making other plans. "You can observe a lot by watching."? Yogi Berra |
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Re: Broken Tap
开云体育Mark, that is very useful information. the set came with drill for each tap. it is interesting, some time ago, i was measuring the nuts that the machine shop made and i found that they had over drilled. now it makes sense. also, did not have a clue regarding dia and depth ratio. as for fluid, i wetted all threads of the tap. any more it just drips. i am also using just 3 in 1 oil not cutting fluid. from your description it appears i need to use more. i guess i need to educate myself a lot more. Imran On Dec 14, 2020, at 1:18 AM, mark thomas <murkyd@...> wrote:
?That's an obvious torque failure.? There's not a single "correct" hole size for a given thread.? The size of the hole determines the "thread engagement percentage" (100% would be the hole is the same as the the outer thread diameter).? 27/64" drill yields 75% engagement, which is too tight for your application.? 50-60% thread engagement is more appropriate for steel in a 1:1 diameter/thread depth ratio, which would be a 29/64" drill.? 75% is appropriate for softer materials, shorter lengths, and machine tool threading.? Get a copy of Machinery's Handbook.? ?Also, lube/cutting fluid has a big effect when threading, did you use plenty? If you're making parts for the space shuttle or for a Felder tool, perfection of thread fit is or course critical, but for a lot of applications, looser tolerances will make threading easier and won't have any significant effect on the holding power.? Just the other day I thread some 1/2-13 holes in 3/8" HR steel and I use 7/16" drill and tap using a hand electric drill, and crank through in just a couple seconds per hole. |
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Re: Broken Tap
开云体育Thanks David. Good idea. do it commonly for holes that cannot be done in DP and need to be perfect. just did not think of doing so for tapping. Imran On Dec 13, 2020, at 11:13 PM, david@... via groups.io <david@...> wrote:
?Imran, it really helps to make a tap guide. ? See pages 222-223 in your Survival Guide. ? David Best https://www.instagram.com/davidpbest/
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Re: Broken Tap
开云体育Imran, it really helps to make a tap guide. ? See pages 222-223 in your Survival Guide. ?David Best https://www.instagram.com/davidpbest/
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Re: Incra LS fence vs. Felder rip fence for x-roll
Like Ariel, I have a few of these magnetic bases lying around the shop at each machine acting as "stops" when needed.? I use it as a "bump stop" on the KF700SP just as frequent as I use the rip fence.? Sometimes, I use 2 or 3 magnetic bases as clamps to minimize stock shifting during a cut or for odd angles.?
SW |
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Re: Broken Tap
开云体育Brian, good to know about accusize. i am very fussy about keeping tap perpendicular checking with small square as i start. with a ratcheting T wrench using both hands there should not be much leaning but i can’t say i did not cause it being new to this. Imran On Dec 13, 2020, at 8:29 PM, Brian Lamb <blamb11@...> wrote:
?Nothing wrong with Accusize tools/cutters, not the highest quality but definitely not the worst. Mostly likely from the looks of it you snapped it off from leaning. Trying to tap 1/2-13 in steel by hand is kind of not going to happen with any kind of consistency.
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Brian Turner
imran
Larry
David P. Best