How does 1090 carbon steel compare to 1045 and 1060 for katana blades?
Updated Feb 2026
The three carbon steel grades - 1045, 1060, and 1090 - differ primarily in carbon content, which affects achievable hardness and certain blade characteristics. 1045 carbon steel at approximately 0.45% carbon provides reliable blade hardness appropriate to a genuine collectible sword, but sits at the lower end of the high-carbon range. 1060 carbon steel at approximately 0.60% carbon is a step up in hardness and is widely considered the workhorse grade of the katana category - it offers excellent blade performance and is found in the majority of mid-tier collectible katana. 1090 carbon steel at approximately 0.90% carbon represents a significant step further up the hardness scale, with blade characteristics that distinguish it from both 1045 and 1060 in terms of achievable surface quality and the range of finish treatments it can support. For collectors who want a steel grade step between the common 1060 grade and the premium T10, 1090 carbon steel offers a meaningful upgrade path with distinctive surface finish options not available in the lower-carbon grades.