I have a job where I make 15k parts a month. They have two countersunk .411 holes. 82 deg. this is in 304.
I got tired of buying carbide countersinks. I now drill and interpolate the minor hole dia. (It's close tol) then I interpolate the ocuntersink with a carbide countersink. I stopped plunging them as the chips would turn into a rats nest where the operator needed to stop the machine to clear the chips ftom the cutter. I'm doing 40 pcs at a time. I tried pecking and that worked pretty well. I was getting about 500 holes out of a countersink. I was running 200sfm and .006 per rev to plunge. I started interpolating the countersinks and the cycle time went down a bunch over pecking and the tool life went to over 6k holes.
Worked for me. |