I am getting my butt kicked all over trying to hard turn an 8620 case hardened part. I don't know if its the lathe, the insert, the bar, or what but its pissing me off. It statrts with a 0.531 inch bore interrupted cut with about 0.005 material, necks down to 0.500/0.501, about 1.7 deep overall. I am running a sumitomo insert, although I tried a kennametal as well. ccmt2151 square insert on a 3/8 steel bar and the finish is not bad but it takes forever and a lot of offset adjustments to get anywhere. Ideally I'd like to find something I can run a couple dozen parts without much adjustment..... but running lathe max 4500 rpm and 1.0 ipm it is not working for crap so far.....
what have you hard turned successfully inside a hole?
what have you hard turned successfully inside a hole?