# TAP PROBLEM



## riversidedan (Jun 12, 2021)

Am self taught with no one around to help and have a alot to learn .......right now am having a tap/die problem, drilled a hole for a tap and the drill was 9/32
then used a M8 1.25 tap. I can get about 1/8in. in  the  6061 part then it stops and wont go any further.  the part that needs die cut is steel which I tried to use a floating die setup from the TS but the die wont start cutting even when I  chamfer the part , I tried both sides of the die still no luck

so we got 2 problems going on , tap and die


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## hman (Jun 12, 2021)

First off, I'll confirm that 9/32 is an OK tap drill for M8x1.25 ... a bit oversize if anything, but that would make it easier to tap, rather than more difficult.  

It's not exactly clear from your photo, but that looks like a bottoming tap.  These have a relatively short nose taper, so you'd be trying to cut too deeply with just the first few cutting edges.  If it's indeed a bottoming tap, change to a "plug" tap and try again.  Also be sure to use a good quality threading lube.

What kind of steel are your tap and die?  "Carbon steel" is sometimes what cheap taps and dies are made of, and is inferior.  High speed steel is what you'd want.


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## riversidedan (Jun 12, 2021)

bottom tap is correct,didnt know a taper tap would make a big  diffrence but will definitly try it. tap/die set from HF .......I know I know just dont laugh too hard, if its that much of a problem they can go in the junk drawer, no biggy


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## matthewsx (Jun 12, 2021)

Taps are one place where quality tools make a big difference. You’ll understand this when one breaks off and ruins the part you’ve spent all day making. Do yourself a favor and buy a quality tap and die for your project, it’s okay to buy them one at a time but don’t trust anything other than something from a real tool supplier. Hardware stores don’t have what you need, either find the commercial tool supply or order online. There are plenty of threads on here about brands and I’m sure someone will chime in with recommendations soon.

I buy plenty of stuff from HF and love them for what they are. But not for taps....


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## Ken226 (Jun 12, 2021)

matthewsx said:


> Taps are one place where quality tools make a big difference. You’ll understand this when one breaks off and ruins the part you’ve spent all day making. Do yourself a favor and buy a quality tap and die for your project, it’s okay to buy them one at a time but don’t trust anything other than something from a real tool supplier. Hardware stores don’t have what you need, either find the commercial tool supply or order online. There are plenty of threads on here about brands and I’m sure someone will chime in with recommendations soon.
> 
> I buy plenty of stuff from HF and love them for what they are. But not for taps....



Truer words have never been spoken.

@riversidedan 

20 years ago I had the same problems your having, with the same cheapass taps.  Buy HSS taps.

I bought my taps a few at a time, as needed until I had a collection big enough to cover all my needs.

Look for something like this









						M8 x 1.25 Metric Taper Tap, High Speed Steel BEST QUALITY Norseman 60234  | eBay
					

High Speed Steel. USA MADE VERY GOOD QUALITY. Be sure to add us to yourfavorites list !



					www.ebay.com
				




Or









						6 Pcs NEW ENGLAND Taps M8x1.25 HSS CROMCLAD Bottom NEW  | eBay
					

<p>6 Pcs NEW ENGLAND Taps M8x1.25 HSS CROMCLAD Bottom NEW. Condition is "New". Shipped with USPS First Class.</p>



					www.ebay.com


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## Jonas302 (Jun 12, 2021)

Even with harbor freight taps you should be able to thread the aluminum though good taps can be had on ebay pretty reasonable  when you get the tapered tap it will go easier use wd-40 type lube on aluminum or tap magic make sure your reversing to break the chips probaly have to clean out the hole a few times then switch to the bottom tap for the last few threads 

If your tying to thread the black stud its probably hardened check it with a file


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## markba633csi (Jun 12, 2021)

Stick with USA taps and dies like Widia and life will be good
-Mark


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## Ulma Doctor (Jun 12, 2021)

OSG make professional taps, some of the best i have used


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## riversidedan (Jun 12, 2021)

thanx guys and yes that stud is hardend, I mostly work with 6061 but ran cross a small stud project.........
what kinda die can I use for that stud material?? and is that M8 1.25 the right size die for the stud??


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## Aukai (Jun 12, 2021)

Are you advancing, and backing the tap to break the chip, and re advancing to go deeper?


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## WobblyHand (Jun 12, 2021)

Is the hole a through hole or a blind hole?  If you get a chance, try a spiral flute tap (for a blind hole).  They pull out the chips as you tap.  No need to advance and break the chip.  It seems like magic, they cut like a dream, especially in aluminum.


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## matthewsx (Jun 12, 2021)

riversidedan said:


> thanx guys and yes that stud is hardend, I mostly work with 6061 but ran cross a small stud project.........
> what kinda die can I use for that stud material?? and is that M8 1.25 the right size die for the stud??


If it’s hardened you may have trouble with almost any die. Usually fasteners are hardened after they are threaded, take a file to it and see if you can make a mark. If not you may have to find a stud that has the right dimensions for your project.

I suppose there may be cobalt dies that could possibly work on hardened steel but it will be much cheaper to order the right stud from McMaster -Carr.

John


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## riversidedan (Jun 12, 2021)

Aukai said:


> Are you advancing, and backing the tap to break the chip, and re advancing to go deeper?


ofcourse, however have come to the realization  I cant make that hard steel stem piece work with the aluminum QCTP handle>>>>>>>so now we gotta make and thread an aluminum stem..


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## hman (Jun 12, 2021)

Almost the story of my life, whether tinkering or machining ... gotta buy a tool with which to fix a tool with which to fabricate a tool with which to do the job at hand.  The fun never stops!


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## riversidedan (Jun 12, 2021)

hey guys for something diffrent howbout a contest>>>>> some guy on  youtube showing how to make a top, so I cranked one out which worked pretty damn good!  was able to get 29 seconds on this one, anyone  wanna challange that??  25 x25 mil... Had to turn down some 1 in. dia 6061


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## benmychree (Jun 12, 2021)

riversidedan said:


> thanx guys and yes that stud is hardend, I mostly work with 6061 but ran cross a small stud project.........
> what kinda die can I use for that stud material?? and is that M8 1.25 the right size die for the stud??


If the stud is hardened, you likely will not be able to tap it without partially annealing it.


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## vtcnc (Jun 13, 2021)

There are carbide taps. Don’t drop it! 

I think John mentioned annealing it. If you are hell bent on modifying that hardened stud that is your only real practical choice.


Sent from my iPhone using Tapatalk


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## Bi11Hudson (Jun 16, 2021)

I would contribute several points, to wit:

1) M8x1.25 is so close to 5/16-18 that it must be measured with a mic, it can't be seen. Size a drill for a 5/16-18 tap. I tend to drill the next larger letter size than that recommended. It still gives a fairly good grip(50%?) but is less work to tap. As I recollect, recommended tap drill is an "F" (.252ish) drill. I would use "G". . . I'm not up so much on fractional sizes, but tap size for 5/16 coarse is 1/4 inch. M8-1.25 will tap to approximately the same size. 1/4 inch, plus or minus 1/64. . .

2) A "carbon steel" tool will (sorta) work on aluminium, and is good for wood and plastic. For use even in mild, untreated steel, it should be a minimum of "HSS", high speed steel. Really good taps, US made, will give the best results and are well worth the cost. In any event, the tap *must* be harder than the material being tapped. How much harder determines how long the tap will last. Carbon steel, about three thread pitches.

3) Even a bottoming tap needs some chip clearance in the bottom of a blind hole. The depth of a drilled hole is reduced by the pointed end of the drill. The hole must be drilled deeper than the desired finished tapped area. How much is a personal judgement dependent on the person drilling the hole, but it must be at least 1/8 inch deeper for a 5/16 fastener. Starting with a plug tap to bottoming and swapping to a finishing tap is the preferred method. If there is room, drill the hole deeper and let the plug tap run enough to get what is needed.

4) Having the tap perfectly square to the *hole* is a given, but must be mentioned. When a tap starts a little off true square, it will drift itself into the side wall of the hole and jam. Sort of like cross threading. . .

There are other factors that need covering, but my mind is drifting so I cannot convey the concepts properly. These are starting points.

.


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