440B Stainless Steel for Knife Blades

AISI 440B Stainless Steel

Manufacturer: Various

440B is a high-carbon martensitic cutlery grade stainless steel that is not commonly seen in knives. More commonly used are 440A and 440C which are both from the same family of stainless steels. 440B can be hardened to about RC58, has good corrosion resistance and is tougher than 440C.

440B is inferior to 440C in edge retention, and edge sharpness, and is not as good a choice as a premium steel. However, 440B is more ductile than 440C and less brittle. It is easier to machine and easier to sharpen as well, making it an cheaper blade steel for production purposes.

440B belongs to the family of stainless steels that include 440A and 440C, the major differences being the variance in carbon content. 440A and 440B are actually indentical aside from carbon content.


C Co Cr Mn Mo Ni P Si S W V
0.75-0.95 - 16-18 <1 <0.75 - <0.04 <1 <0.3 - -
Values are shown in percentages.