I found this on the Swamp's site:

SR-101 Steel


(Think of it as 52-100 tool steel with added Kryptonite)


SR-101 Steel is the combination of an extremely fine-grained tool steel and a proprietary multi-step tempering protocol. This process includes the incorporation of a deep cryogenic treatment for grain refinement which adds greatly to the overall toughness and strength of what will most certainly prove to be your favorite blade.

AND you might take a look at this thread

http://forums.scrapyardknives.com/ubbthreads.php/topics/220830/INFI_vs_SR_101.html

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