klassenjcnc

Here is my scar from work. Just a little one. Was using a hook to grab chips of a big drill I was using. Chip whipped around and lopped off a chunk of my thumb. Managed to stick the chunk back on and after a couple of days it was all grown back together. I guess a 6" hook doesn't really do much lol #mthpad

Here I am again. Need some advice. 4140 HTSR. 5/8-11 UNC, 1.5" deep through hole. Form tap we had chipped a previous time we tried to do this job. Bought a spiral point Walter tap that is supposed to work for this material. First try a week ago running at 25 sfm with coolant, tap blew up after 36 holes. Reorderd 2 taps, thinking it might have just been a chip issue the first time, tap chipped after 2 holes. Tried tapping oil and slowed down to 15 sfm, tap chipped after 1 hol...e. Starting the tapping cycle 0.2" above hole. Coolant at 14%. Oemeta semi-synthetic coolant. Water quality: no clue. Coolant gets foamy with use. What should we be trying or doing different? How have you tapped at lesst 80 holes successfully in this material? What is the most likely cause of our problems.

Another day, another part that perfectly fits in the machine. Lovely 4130 material to work with as well!

First time I've topped 10 MRR! . Just a little benchmark I set for myself a while back. For those who aren't machinists, it means Material Removal Rate in cubic inches per minute lol