Cut Tap VS Roll Form Tap Question

Why guess?

Call the customer and ask him to measure the taps he wants to use.

If the customer does not yet have the taps, call the customers supplier of taps.

If you knew the customer, you'd know that asking here has a better chance of getting the correct answer... :)

Joe,

I think you'll find that most taps of similar sizes will have the same shank diameters. Whether they're inch *or* metric, roll form *or* cut taps.

I just checked a few taps and found that the 1/4-20, 1/4-28 & 1/4-32 cut taps have the same shank diameter as the 1/4-20 roll tap, *and* the M6x1 cut and roll tap. My Greenfield M12x1.75 roll tap has the same shank diameter as the OSG 1/2-13 cut tap. The 5/16-18 cut and roll taps are the same, and the 3/8-16 cut and roll taps have the same shank diameter.

Here's what I wrote in a response to BD in another thread (Tap Collets....) a few weeks ago:

That has been my personal experience as well. However, having run across a few metric shank taps and "strange" shank taps over the years, I figured I'd try to learn about the standard.

Looks like you are correct. Folks here as well as a few other places seem to agree that there is a *very* good chance the shanks and square drives are the same or compatible.

SNIP

Excellent then and excellent now. Thank you again.

Does anybody use sti roll taps? I was told that Emhart(Heli-coil) doesn't advise their use. I guess Balax see's it differently.