Atlas Steel Sp. Alloy-10 Knife Steel
Composition Analysis Graph, Equivalents And Overview

Sp. Alloy-10(Atlas Steel) - Water hardening tool steel. Quite popular with custom knife makers, beginners and seasoned experts alike. Easy to work with, decent edge holding and ok. toughness, depending on the heat treatment. Maximum working hardness is in 63-65 HRC Range. Obviously, you won't be getting much of the toughness at 65hrc, however edge holding and cutting performance for thin edges increase accordingly.
W2 a is just as bad(read, broad) in terms of specification precision as AISI W1 steel. Carbon varies from 0.85%-1.50%. Huge variation for an alloy. Trace amount of Chromium serves primarily as a carbide former, may be adds something to alloy strength as well, but nothing in terms of stain resistance, too little of it(Cr). W2 maxes out 64-65HRC when enough Carbon is present, and works quite well at that hardness levels as a light use knife. Pretty good with polished, thin edge at 64HRC. I've seen various types of knives in all sizes, starting from small folders and ending with rather large kitchen and utility knives. Overall, it's a decent steel, non-stainless, won't win any awards in abrasive wear resistance department, but will do variety of jobs.

Manufacturing Technology - Ingot

Country - United States(US)

NOTE - Approximate composition based on manufacturer's or standard reference information and other alloys in the same reference group is shown.

^* - Listed as an equivalent or replacement for alloys in this group.