[BlueSkyJaunte]

Grain size is primarily a function of the heat treatment. A high-quality heat treatment of multiple normalization cycles followed by proper hardening and tempering results in a nice tight grain structure. Of course the heat treatment regimen must be tailored specifically to the steel chemistry (carbon content + alloying elements). But a knifemaker who knows what steel he's using and what the proper heat treatment protocol is can make a very durable, wear-resistant blade as long as the steel itself is what it's advertised to be.