Running taps; fast or slow?

1/4-20 in Aluminum I usually do 800 RPM, in steel 400 RPM. Spiral pointed or Spiral flute.

I've been to shows where they were running 10-32 in Alum at 5000 RPM.

Remove 333 to reply. Randy

decent brand and the steel not overly hard. I've run 1/4" 20 tap at 100 R PM. The taps last quite a long time; never had breakage at those speeds. I can understand running the taps faster when high production is going on. But be prepared for breakage. I hate running taps fast. Digging out a br oken tap is something I don't like to do. Some people say that you should run taps fast, and let the tap itself pull itself in(whatever that means). I disagree. Except as noted in a high production environment.

I can see the point there if you're running production. If you're tapping

8 holes, there is no need to run that fast. As an aside, my partner on the opposite shift ran all of his taps at 100 RPM. The reason is that it was easier to program than let's say running a tap at 230 RPM(according to tap diameter).

ection is active.

Generally speaking you can run a tap as fast as you would run the same sized drill in the same material, the problem being you need to be able to control feedrate accordingly, actually doing this depends largely on the machinery and tooling that you have at your disposal.

decent brand and the steel not overly hard. I've run 1/4" 20 tap at 100 RP M. The taps last quite a long time; never had breakage at those speeds. I can understand running the taps faster when high production is going on. But be prepared for breakage. I hate running taps fast. Digging out a bro ken tap is something I don't like to do. Some people say that you should r un taps fast, and let the tap itself pull itself in(whatever that means). I disagree. Except as noted in a high production environment.

I prefer to thread mill when I can,and roll form when I can. These are the speeds I generally use,G84 coded,up to #10 in Alum around 1500rpm ,#10 to 5 /16 around 800 rpm, to 1/2 around 500 rpm. In steels I peck tap and general l don't excede 400rpm. very rarely excede 1/2 dia and when I do I thread mill.