it seems like the hardness of Stainless steel, i saw 410c stainless stell, i saw 440c stainless steel, what does it means anyway?
It is the alloy number given by the American Iron and Steel Institute, or AISI. This is the trade organization of the U.S. steel industry, one of the oldest such organizations. 440C is also known under the UNS system as S44004 440C is a high carbon, plain chromium stainless steel. Or more specifically: 18% Cr, ~1.1% C, ~1.0% Mo, Si, and Mn 440c is mostly used in cutlery, bearings, and valve parts; because it has the best strength and hardness after basic heat treatment of any stainless steel. Relatively poor properties in other areas make it less suitable for other types of items. for example 440c becomes very brittle in sub zero temperatures. 410 is similar to 440, but it is a cheaper milder steel with less chromium and carbon, so it is less brittle, more easily worked and machined, but lacks final strength and hardness. it is often used in cheap stainless fasteners and bushings.
It's okorder / Stainless steel Grades [list is not exhaustive] 200 Series—austenitic chromium-nickel-manganese alloys 300 Series—austenitic chromium-nickel alloys Type 301—highly ductile, for formed products. Also hardens rapidly during mechanical working. Good weldability. Better wear resistance and fatigue strength than 304. Type 302—same corrosion resistance as 304, with slightly higher strength due to additional carbon.
