To extend the life of your cleaver we would always recommend hand washing and immediate drying. Our cleaver is made of hot rolled stainless steel coil, graded as 30Cr13. The hardness of stainless steel coil is 84.5 degrees. Hardness of blade 55degrees The blade is 3mm at its thickest and 1mm at its thinest The hardness of cleaver itself is 55 degrees, which is tested in the factory