The Camillus TigerSharp Replacement Blades includes 4 3.35" 420J2, Silver Titanium Bonded blades. 420J2 is a stainless steel that has a low carbon content and has a high chromium content, making it a shock absorbing steel that bends instead of breaking. Additionally, 420J2 has excellent resistance to corrosion, high stain resistance and fair edge holding capability. The Titanium Bonding treatment for each blade is also not achieved by painting or plating. Rather, it is an application of a unique formulation of titanium and chromium nitride to the surface of cutting blades that actually penetrates the metal to create a permanent bond. The bonding process affords essential benefits, such as enhanced corrosion resistance, adhesive resistance, and exceptional edge retention by making the metal 3x harder than untreated steel. Even though these are replacement blades, don't mistake them for cheap ones. Each blade will hold its own against the elements and diverse tasks they are put through just as well as any of our knife blades.