A little bit ago, I asked some questions about carbide inserts for wood turning and got some helpful replies. I bought a round, square with radius and a diamond detail insert from AZ Carbide and they were not very expensive.
I mounted these to 3/8" and 1/2" square steel bars by filing the end of the bar down to receive the insert. It was difficult to get the area flat. So, I used my Dremel tool set up like a router with a grinding stone. I held the bars down and then gradually ground the surface down flat. Surprisingly, it worked very well. The inserts required 4-40 and 6-32 tapped holes. The small 4-40 was difficult as I had not tapped a hole in awhile and this was a small tap. After tapping the holes, I shaped the nose of the bars to correspond to the carbide insert mounted on it.
I had some ash and prepared blanks by routing a groove into them and then gluing them together to give a snug fitting square hole. The bars are held in by a 6-32 machine screw through the handle and into the bars. The ferrules are copper end caps that were polished. The finish on the ash was a dark Danish Oil and wipe on poly.
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I am really pleased with the way these cut and they stay sharp and especially happy with the low cost to make these compared to buying the handles.