Grade 420 Stainless Steel (Cond-A, Modified)

Grade 420 is hardenable martensitic steel. Grade 420 stainless steels have high carbon contents and are made up of at least 12 percent chromium. It is the hardest type of stainless steel with a chromium composition in this range and is available in numerous variations including condition A and modified forms. These variants have undergone additional treatments to boost or alter specific performance characteristics including strength, ductility, and machinability.

Performance Characteristics of Stainless Steel Grade 420

From a general standpoint, stainless steel grade 420 (Cond-A, Modified) is highly ductile when processed in its annealed form. It also displays outstanding oxidation resistance when it has been hardened, polished or surface-ground. Grade 430 alloys, with their higher chromium contents, are more resistant to a broader range of corrosives.

This stainless steel grade is widely used in the manufacture of shear blades, surgical instruments, and needle valves. It is also the standard alloy in stainless steel cutlery. Hardened forms of stainless steel grade 420 resist the following types of corrosive substances:

  • Freshwater
  • Alkaline materials
  • Mild acids
  • Food & organic compounds
  • Air

These alloys also resist wearing from heat when exposed to temperatures of up to 650° C (1200° F). They can also be machined fairly easily in their annealed state. They anneal at temperatures between 1550-1650 F (843-900 C). With that being said, they are not quite as versatile as 416-grade stainless steel alloys. When it comes to hardening, 420 grade needs to preheat, then heat to 1800-1950 F (982-1066 C), soak that temperature and air cool or quench in warm oil.

Stainless Steel Grade 420 

Chemical Composition 

UNS: S42000 / TYPE: 420 

 Carbon (C)Manganese (Mn)Phosphorus (P)Sulpher (S)Silicon (Si)Chrome (Cr)
Min  0.15         12.0
Max   1.00 0.040 0.030 1.00 14.0

Stainless Steel Grade 420 

Mechanical Composition

Grade   UNS NumberTensile Min (psi)Yield Min (psi)Elongation Min %Reductions Min %Hardness BHN
420 S42000          
Cond-A   * * * * 241 Max
Modified   110,000 80,000 20 40 207-235


Choosing the right stainless steel alloy for a specific application can be a difficult task, given the minor variations in performance characteristics seen in both standard and variant metals. For more information about stainless steel alloy 420, or to inquire about its condition A and modified variants, please contact a knowledgeable Ram Alloys representative today! 

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