Re: Taps: form vs. cut

The Pre-Meltdown Kid wrote:
Awl--

Actually bought a 6-32 form tap, got the 3.1, 3.2, 1/8 tap drills for the various % thread stuff.
Which one would you all use? In 6061.
Rigid tapping, of course .

I've used 1/8" and 3.1 mm with good results






I know form taps are better (at least more convenient) for blind holes.
But blind holes, chip consideration, and cost aside, under what circumstances are cut taps preferred, if ever?
I'm guessing form taps would work better in alum/brass than in SS.

I've started using spiral FLUTE taps with good luck. I've had people complain about form taps being hard to start because when the thread is formed it leaves a small "V" at the crest of the thread.



Also, which is better ito the best fit/holding strength for a screw? Material dependent?

Forming strengthens the material in most cases. Also you should be using course threads in soft materials, course threads in stronger materials. I'm not sure why, at least here in Silly Cone Gulch, I see all these #10-32 screws in aluminum but it's almost universal.

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Regards,
Steve Saling
aka The Garlic Dude ©
Gilroy, CA
The Garlic Capital of The World
http://tinyurl.com/2avg58

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