Winston

Just for kicks, I decided to look at a few different chisels under the microscope, comparing a buffed chisel to an unbuffed one of the same type. No edge durability test here; just some pictures of buffed and unbuffed chisels. The buffed chisels were sharpened to 4000 grit and then buffed; the unbuffed chisels ended on a Shapton Pro 12000.

Just from looking at the pictures, you can tell that the Shapton Pro 12000 won't create an edge that is as uniform as the buffed edge. I think the buffing changes the edge in three ways: it makes the edge more uniform, it increases the angle, and it rounds off the apex. I wonder how important each of these factors is for edge durability.

Previously, I showed a buffed and unbuffed Buck Brothers chisel. Here's the unbuffed Buck Brothers chisel:

And two shots of the buffed chisel with different lighting:

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I also did the same with a Veritas PM-V11 chisel. Unbuffed:

Buffed:

The results are pretty similar, but the buffing didn't smooth it out as much. I don't know for sure, but it's probably because the metal is more resistant to buffing, and because I didn't buff it for as long.

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I also tried it out on some Japanese HSS chisels. I believe these chisels were billed as semi-HSS chisels by Stu at Tools From Japan, when his store was still open. The unbuffed chisel looks pretty similar to the other ones we've seen.

The buffed chisel has these little dots in it.

Looking at it with a higher magnification, you can see that they're bumps that stick out of the rest of the metal. I'm guessing they're carbides that remained in place while the surrounding steel was worn away. Pretty cool that they can be seen with the microscope!