410 vs 420 Stainless Steel: Martensitic Workhorses

 

410 contains 11.5-13.5% chromium and 0.15% max carbon. 420 has 12-14% chromium and 0.15-0.4% carbon, with the higher carbon allowing for greater hardness after heat treatment.​

 

420 reaches 50-55 HRC after heat treatment, harder than 410's 40-45 HRC. This makes 420 more wear-resistant, suitable for cutting tools, while 410 balances strength with better toughness.​

 

Both offer moderate corrosion resistance in dry environments, with 420 having a slight edge due to higher chromium. They can rust in moist or salty conditions, requiring protection in harsh settings.​

 

410 is more formable in its annealed state, easier to bend and shape. 420 is harder to machine but can be heat-treated to sharper edges, making it better for knife blades and precision parts.​

 

Where are 410 and 420 commonly used?​

410 is used in valve parts, pump shafts, and automotive components. 420 finds applications in knife blades, surgical tools, and valve components where hardness is critical.