Charlie-III | 07-05-2011 06:51 AM | Quote:
Originally Posted by Reflection
(Post 3171566)
We typically use rolled threads (form taps) when taping a smaller size like 3mm or #6 and smaller...in aluminum. Can't do that in steel, stainless or anything hard. In hard material, a hole a few thousandths bigger will be allot easier on your taps. Using spiral flute cut taps help in hard material since they pull the chips out of the hole instead of pushing them down into the hole. From my limited experience, the chips coming off the tap in the hole is what breaks allot of taps. | Yep, I used to do thousands of #10 rolled threads in aluminum in a machine shop. Much better thread than cut.
As to chips breaking taps, having them go to the bottom of a blind hole can bind the tap & break it.
Not backing the tap off to break chips can be as bad (in 3/4-1 turn, back 1/2 turn.....).
Bending taps also breaks them off.:roll:
Funny story....one place I worked, we ordered TiN taps for a job, our purchasing dept bought HSS taps & had them sent out for Tin coating. They couldn't figure out why we were pissed when they came in.:roll::lmao::lmao: |