DIYbanter - View Single Post

So my question is something like?

Can someone give me the 5 min class in what kinds of taps are used for
what?

Do you use a different tap for
Aluminum?

Yes and No

Steel?
Yes and No

Plastic?
Yes and No

When do you use a 4 flute, when do you use a
tap with other than 4 flutes?

4 Flute would be a general purpose tap. There are generally three types,
starting tap, mid tap and a bottom tap. Starting tap has an extended
taper lead-in to help you get it started in the hole, mid tap has a
shorter taper and goes in after you get the threads started with the
starter tap, and a bottom tap is used to finish up the threads to very
close to the bottom of a blind hole.
You would normally use a 3 flute tap for gummy materials needing a lot of
flute clearance like aluminum and copper, etc.
High helix taps are also for stringy/soft materials like aluminum and
plastic. These are good at evacuating chips from the cutting zone.

What is the strongest tap (aka one I won't snamp off)

About a 3" or bigger.

Any taps with a leading guide pin that aligns with the hole for hand
tapping?

I've not seen any of these, however they do make a drill/tap combo.

What is a roll tap?

A roll tap doesn't "cut" material away, instead it "compresses" the
material into the thread shape. This is normally a stronger thread form
used in softer materials.

Paul