US Patent 8621757 Coated cutting edge of a blade member

In a cutting edge of a razor blade, a non-nitrided layer containing Ti, Al, and Cr formed on opposite surfaces of a base plate as a portion of a coating layer. A remaining layer containing Ti, Al, Cr, and N formed on opposite surfaces of the non-nitrided layer as a portion of a nitrided layer of the coating layer. A surface layer containing Ti, Al, Cr, and N formed on opposite surfaces of the remaining layer as a portion of the nitrided layer of the coating layer. A fluororesin layer formed on opposite surfaces of the surface layer with a bonding layer containing Cr and Al in between. The coating layer further improves the cutting edge, enhances cutting performance of the cutting edge, and maintains the enhanced cutting performance to improve the durability of the cutting edge.