roll form tap better in 316 stainless?

[stovepipesteve]

i have never used roll form taps, but i think they might be more worth trying on the job im running now.
im tapping 316 SS ,( 1/4-20 about .7 deep.)
So are roll form taps better than standard taps? in what materials? speeds vs. standard taps speeds and feeds?
Like i said, i have never used them before, but iv been machining for 15 yrs. ( alittle late in the game, i know).
honest opinions apperciated.

[extanker59]

I would try your roll forming tap. Just be aggresive with it. Keep SFM up to the highest in the range for your tap (OSG exotap nrt forming claims 20-45 sfm) with 316. SS taps fairly well with forming taps. The only problem I had was fine tuning my hole diameter to make the form tap flow the metal to close up the crests. It looks like a double thread sometimes if the hole is too big. It may take some trial and error to get it. My one tap lasted over 300 holes and the job ended at that so I'll never know how much more it would have gone (this was in 303 SS).
I'm a bit late in the game too so maybe some long timers have other views.