I have a job to tap 100 or so 1/2-13 blind holes into both cold roll and hot roll. ive been getting taps from McMaster but lately, they don't seem to be very good quality and cut hard. Anyone know of a better name brand than what they sell? thanks
yeah same brand I get. maybe I just got a couple of rejects ..I get a lot of taps from McMaster and a lot of time they are GTD or widia brand.
i am using spiralflute. I have not tried a larger hole.so for blind holes are you using spiral flute taps?
if they are hard to cut with, have you tried going up in drill bit one size so from a 27/64 to 7/16, or a 10.8mm?