Nachi-Fujikoshi SRS-15 Knife Steel
Composition Analysis Graph, Equivalents And Overview

SRS-15(Nachi-Fujikoshi) - High speed, PM tool steel, Used in Akifusa(and Artisian) kitchen knives and by few other Japanese makers. SRS-15 typical hardness 63-64 HRC. Works well in the kitchen with acute, high polished edge. Haven't seen it in other types of knives or from other makers. Unsurprisingly, as I've learned years later, SRS-15 is an exclusive steel, so not everyone is allowed to use it. Spyderco wanted to use it in their sprint run circa 2020, and was not allowed to do so. Instead, they had to go with a modified version, SRS-13 steel. From my experience, SRS-15 is fairly easy to sharpen and holds edge fairly well. Sure, there are better performers out there today, but it can hold its own, and outperforms many popular steels on the market. Toughness is also pretty good even at 64HRC, at least for the kitchen use. I haven't observed any significant chipping on my Akifusa gyuto during more than a decade of use. Stain resistance is also good, at least for me that works well, no discoloration or any signs of patina, but on the other hand, I'm the guy with dozens of non stain resistant(also often incorrectly called carbon steel) knives which don't rust in my kitchen either, but patina is definitely present on those.

Manufacturing Technology - PM

Country - Japan(JP)

Known Aliases:
Nachi-Fujikoshi - SRS15