Colt Boot Knife steel

[Hunterarrow]

Does anybody know what kind of stainless steel they use for Colt Boot Knife?
I gave this knife to a fisherman and he says it doesn't take any rust. The blade is made in China, I think.

 

[Planterz]

I remember seeing some Colt branded slipjoints that were the same as Rough Riders or Steel Warriors (I don't remember which). RR and SW use 440A steel, or some analogous equivalent. I'd expect this knife to have the same.