MTBob
Well-Known Member
After seeing a number of posts on KD and watching a couple of videos from Pop's, I finally made a knife straightening peening hammer. I tested it on a post heat treated 52100 think chopper that's in the larval stage. It had about 1/16" deflection starting just behind the ricasso.
I had a bunch of common ball bearings (not sure what they are made of) and an old hammer that had a somewhat flat face to hold in the mill. So, I drilled a hole in the hammer face and put a 1/2" ball bearing in it. I over drilled the hole depth by about .090" and used G-Flex epoxy to hold it in. I thought about silver soldering it in, but wanted to give G-Flex a try.
Not knowing what the ball bearing material is, I thought it might not work that well, either crack or not indent the knife.
After a few minutes of tapping, this is what the hardened knife looked like. It really didn't take all that much whacking to move the metal. The blade is .100" thick.
A crappy photo but indicative of the blade straightness.
Since I thought that I needed a tungsten carbide ball, I ordered a few 1/4" balls from Amazon. I'll install one of those in the peening end of the hammer.
But, I'm kinda assuming the mystery balls I have had for a few decades are not tungsten carbide, it still seemed to work well in this application.
I had a bunch of common ball bearings (not sure what they are made of) and an old hammer that had a somewhat flat face to hold in the mill. So, I drilled a hole in the hammer face and put a 1/2" ball bearing in it. I over drilled the hole depth by about .090" and used G-Flex epoxy to hold it in. I thought about silver soldering it in, but wanted to give G-Flex a try.
Not knowing what the ball bearing material is, I thought it might not work that well, either crack or not indent the knife.
After a few minutes of tapping, this is what the hardened knife looked like. It really didn't take all that much whacking to move the metal. The blade is .100" thick.
A crappy photo but indicative of the blade straightness.
Since I thought that I needed a tungsten carbide ball, I ordered a few 1/4" balls from Amazon. I'll install one of those in the peening end of the hammer.
But, I'm kinda assuming the mystery balls I have had for a few decades are not tungsten carbide, it still seemed to work well in this application.