- Joined
- Jan 20, 2018
- Messages
- 5,647
I was trying to make a tool height gage (for quickly setting tools to center height) for my SB Heavy 10L yesterday. I found a suitable base, an old, hardend and ground top-jaw from an unknown chuck (I have 2 of the 3). Then I went looking for a piece of 3/4 x 1 about 6 inches long to bolt to the base. I have a bunch of odd pieces of tool steel that Fred gave me along with the lathe and mill. In that I found just what I was looking for, 2 pieces of 3/4 x 1 x 6. I took one and cleaned it up a little. It had saw cut ends and ground finish, like tool steel flats. It needed to have the end squared and tapped 1/2-13. Assuming it was probably D-2, I decided it would be better to try this in the lathe, so I put on the 4-jaw and indicated the part in. I started facing it with a CCMT insert, which was working, but pounding hard enough to make the the compound jump noticeably. I switched to the 100 deg. corner of a CNMG 432, which was much better but still pounded hard even at .010 DOC. After facing, it was time to drill the pilot hole for tapping. I couldn't even make a mark on the end with the 1/4" stub drill I had chosen. I tried a center drill, same thing. That's when the light came on. I pulled it out of the chuck and tried filing a corner. Nothing, the file just slid right off. What I had found was a pair of shop made 3/4 x 1 hardened and ground parallels!