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420 is a martensitic stainless steel with 12% Chromium, which gives the material good corrosive resistance. 420 can be heat treated to achieve greater hardness. Its best corrosion resistance is achieved when the metal is hardened and surface ground or polished. There are also variations of 420 that contain molybdenum (for better corrosion resistance), sulfur (for better machinability) or vanadium (for higher levels of hardness). There is also a higher carbon version of 420, 420C. This material is commonly used for cutlery, medical instruments, scissors and straight edges. 420 is almost never used in an annealed condition.
Component Elements Properties |
Percent |
Carbon (minimum) |
.15% |
Manganese (maximum) |
1% |
Phosphorus (maximum) |
.04% |
Sulfur (maximum) |
.03% |
Silicon (maximum) |
1% |
Chromium |
12-14% |
Physical Properties (Annealed)
Property |
Value |
Property |
Value |
Tensile Strength, maximum |
100 ksi |
Elongation in 2 inches (50.8 mm) or 4D, minimum |
|
Nominal Thickness |
|
Up to 0.030 inch (0.76 mm), excl |
12% |
0.030 inch (0.76 mm) and over |
15% |