Small Machine Screw Tapping Issue

[historicalarms]

As mentioned earlier axial alignment is probably the most important factor when tapping small holes.

I've tapped a couple thousand 2-56 holes and a few hundred 0-80 holes in aluminum, bronze, brass using this tap guide and a regular T-handle tap holder. The tapping block holes are dimensioned to match the standard tap shank diameters with a few thousandths clearance. I've never broken a tap using this guide unless I accidentally bottomed a 0-80 in a blind hole - but then that one's on me

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Brent

That's one of the reasons I marveled at your work when I got a chance to look at it "in-hand"...the "small screw installations just scream "quality care & attention".

 

[Susquatch]

I use a little iPhone app called iEngineer

I need to tap some small machine screws into some beefy steel. The screws are 7/64 in diameter, and appear to be 40 NC. I can't seem to find a tap for these screws, or a recommendation for drill hole size. The screws are those small ones you typically buy at electronics parts stores to mount PCBs using standoffs.

For those who prefer the Android platform, I use an app called "Tap and Drill Chart Calculator". It lists preferred drill size, alternate drill sizes, %thread, material, tap type, metric, sae, and many other options. I love it. It's my goto reference for all thread jobs.

I like to tap small holes by hand on my drill press with the press only providing alignment and spring pressure through a small spring loaded tap centering device, and me doing the all the work.

Lastly, Joe Pie has a You Tube video on tapping small holes. It's golden.

 

[Susquatch]

As mentioned earlier axial alignment is probably the most important factor when tapping small holes.

I've tapped a couple thousand 2-56 holes and a few hundred 0-80 holes in aluminum, bronze, brass using this tap guide and a regular T-handle tap holder. The tapping block holes are dimensioned to match the standard tap shank diameters with a few thousandths clearance. I've never broken a tap using this guide unless I accidentally bottomed a 0-80 in a blind hole - but then that one's on me

View attachment 15546

Brent

Holy smokes @Brent H I googled the writing on that fixture and all I got was Escort Services........

I like the tapping block though. Can you tell me where to get one? If not, maybe I'll just make one. It doesn't look too hard. I make one-off tapping fixtures all the time for big jobs on farm equipment.

 

[CalgaryPT]

This was my first purchase from Grizzy years ago when they just started shipping to Canada. It's a hand taping machine I bought for a large project that had hundreds of taps. I would get tired after so many holes, and I couldn't hold them straight. I never broke another tap once I got this machine, although I rarely use it these days unless I have lots of holes to tap at once.

 

[eotrfish]

@Susquatch

I picked up the tapping block at a trade show about 20 years ago. It is made by OMW Corp. They seem to be still in business but I couldn't find the block on their website.

I did find reference to the block at https://littlemachineshop.com/images/gallery/Instructions/TappingBlockInstructions.pdf

 

[CalgaryPT]

For those who prefer the Android platform, I use an app called "Tap and Drill Chart Calculator". It lists preferred drill size, alternate drill sizes, %thread, material, tap type, metric, sae, and many other options. I love it. It's my goto reference for all thread jobs.

I like to tap small holes by hand on my drill press with the press only providing alignment and spring pressure through a small spring loaded tap centering device, and me doing the all the work.

Lastly, Joe Pie has a You Tube video on tapping small holes. It's golden.

True, the iEngineer app is missing the %thread, which is too bad, but still a handy reference.

 

[CalgaryPT]

As mentioned earlier axial alignment is probably the most important factor when tapping small holes.

I've tapped a couple thousand 2-56 holes and a few hundred 0-80 holes in aluminum, bronze, brass using this tap guide and a regular T-handle tap holder. The tapping block holes are dimensioned to match the standard tap shank diameters with a few thousandths clearance. I've never broken a tap using this guide unless I accidentally bottomed a 0-80 in a blind hole - but then that one's on me

View attachment 15546

Brent

Big Gator Tools makes tapping some decent drill and tapping guides. I have the drill guide, but not the tap guides: https://www.shop.biggatortools.com/main.sc

 

[Tom Kitta]

If you need some taps I have some really tiny ones.

 

[CalgaryPT]

If you need some taps I have some really tiny ones.

Thanks Tom. On Monday I am rethinking my design—not because of the tapping but I noticed what I think is a better way to mount things that doesn't require tapping. Whenever I think up a different approach, I always sit back for a day or so and do a re-think.

 

[YYCHM]

Ok, so now you have to tell us what it is that you're making...

 

[CalgaryPT]

Ok, so now you have to tell us what it is that you're making...

Not happening Craig Stay tuned in a few weeks if all goes well.....

(Hint: It involves metal.)

 

[CalgaryPT]

Found a couple of 4-40 taps together with #43 drill bits for $23 at Calgary Fasteners. These guys have been pretty decent to me over the years. Lucky for me too...Amazon wants $44.10 for a set of ONE tap and drill bit. I guess theirs are made of gold and pre-lubricated with unicorn tears.