Hand Tools

Subject:
The chase

Bill Tindall, E.Tn.

chasing toughness for woodworking tools is a bit of a waste, especially if you have to give up hardness to get it.

You always give up hardness for toughness. Hence, optimization is the unavoidable name of the game.

In an earlier thread it wasn't me that was reporting chipped edges. It would seem that you have discovered that "chasing" toughness is not a waste. Complaints about A2 chisels frequently involved chipping at low chisel angles. Chipping comes from inadequate toughness. The chisel I made from M2 was a failure. It was plenty hard, and chippy at typical bevel angles.

Most people sharpening are not going to employ the complex bevel geometry you do to compensate for the failure mode of the tool. A chisel is going to have to survive with a flat bevel that enables acceptable penetration. It will best survive when the hardness and toughness is optimized. Lee Valley took this approach and wound up with a chisel nearly as good as the best Japanese chisels made from some color of steel (as I think I correctly recall from a report from Derek).

If optimizing the bevel is fair game then chasing steel has been demonstrated as a "waste". In a practical situation of building ash drawers a Narex with a small convex bevel refinement did as well as any chisel. It survived a set of drawers. Who would need more? You reported similar results from Sorby which is a notoriously soft chisel, or even cheep chisels.

Your discovery of the benefit of convex bevels ended any practical interest in chasing steel properties. However, I more than most understand the joy of experimentation.

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