Hi all. I've got a project going involving boring a hole down the middle of a bronze bar, 3" OD. The material is alloy 630 Ni/Al/Bronze.
The issue I'm having is that the drills are having a harder time than I expect getting through this thing. I started with 1/8", which worked ok, but when I went to 1/4", I got a lot of binding. I made sure the bit was plenty sharp, but I'd go about 100/200 thousandths, and lathe would slow down, start spinning the bit in the chuck, etc. I had to keep backing it out to clear (not very many) chips, and restart. After I got through it, I went to 3/8", and got the same thing.
I'm pretty sure my drill bits are in good shape, I've used them doing similar things in steel and aluminum with no trouble. It seems like there's something different about this material which is fighting me.
Any hints welcome.
The issue I'm having is that the drills are having a harder time than I expect getting through this thing. I started with 1/8", which worked ok, but when I went to 1/4", I got a lot of binding. I made sure the bit was plenty sharp, but I'd go about 100/200 thousandths, and lathe would slow down, start spinning the bit in the chuck, etc. I had to keep backing it out to clear (not very many) chips, and restart. After I got through it, I went to 3/8", and got the same thing.
I'm pretty sure my drill bits are in good shape, I've used them doing similar things in steel and aluminum with no trouble. It seems like there's something different about this material which is fighting me.
Any hints welcome.