Allegheny Ludlum Exohard Knife Steel
Composition Analysis Graph, Equivalents And Overview

Exohard(Allegheny Ludlum) - Cobalt-Molybdenum high speed tool steel. To some degree it is AISI M1 high speed steel enhanced. More Carbon, about 0.25% more, and more importantly ~5% Cobalt, not present in AISI M1 steel. That cobalt allows M47 to achieve 70HRC max hardness and stay hard at high temperatures. Good luck finding a knife maker who'd make a knife at that hardness though :) I've seen very few knives at 68 or even 69HRC, never 70HRC, which is where Rockwell C scale ends by the way. High carbide volume alloy and it is difficult to machine, heat treat isn't easy either. Will work better with coarse edge, ~15° per side angle. As many other high speed tool steels, perhaps it's better suited for light use, high performance cutters, however AISI M4 high speed steel did win a lot of cutting competitions which involve a lot of chopping and prying. I've never seen M47 steel chopper though, but can't dismiss the possibility either. Wear resistance is very high, that's not really debatable.

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.