Hand Tools

not a new property..

David Weaver
..but a test for fine edge holding would be interesting (which would be different than intentionally notching an edge or some of the toughness tests).


The chart of A2 items is interesting - around 61 hardness and then higher for AEBL and Niomax, there's high hardness and toughness better than white steel.

i doubt they'll make better chisels despite hitting higher hardness and better toughness (i believe niomax is larrin's creation, using niobium carbides to reduce carbide volume and improve toughness).

I'll have to ask larrin about this. I'm sure he has an answer as he often talks about hardness and geometry and fine edge holding above getting fascinated with abrasion resistance and alloy charts (as in, the steel choice is down the line after other characteristics are accounted for).

Strength is obviously measured in several common ways, but not sure if they cover fine edge holding (tensile strength, yield strength).

An undesirable steel for a lot of purposes (one that fails shortly after it begins to deform) is described as "brittle". White steel is a brittle steel, but makes a fabulous chisel.

Why is this important rather than just working through the knife charts? Well, if we don't really challenge toughness (and chipping isn't so much a toughness issue in regular use, rather a defect or geometric issue - or overhardness), then maybe toughness isn't that big of a deal. Certainly, 3V at 61 hardness would make a much better chisel than at 59, even though its probably half as tough. Same with plane irons (i'd like it better as a knife, too, but I don't hammer knives or twist them, either).

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