420
Alloy 420 is a 12% Chromium martensitic stainless steel known for its high hardness. It finds wide-ranging applications, including surgical and dental instruments, scissors, needle valves, gears, ball bearings, magnets, and more. However, it is not suitable
for use in springs or heavily stressed parts operating at sub-zero temperatures.
Chemical Composition Limits
| Weight% | C | P | Si | Fe | Mn | S | Cr |
| Alloy 420 | 0.15 min | 0.040 max | 1.00 max | Bal | 1.00 max | 0.030 max | 12-14 |
Mechanical Properties
| Material | Tensile Strength (Mpa) | Proof Stress 0.2% (MPa) | % Elongation in 2″ | % Reduction of Area | Hardness Brinell |
| Alloy 420 Ann Room Temp 1″ Round Bar | 655 | 345 | 25 | 55 | 196 |
Specifications
| AMS 5506 Sheet / strip / plate | AMS 5620 Bars / forging (free mach) |
| AMS 5621 Bars / wire / forgings | QQ-S-763 |
| ASTM A276 / ASME SA276 | ASTM A314 / ASME SA314 |
| ASTM A484 / ASME SA484 | ASTM A580 / ASME SA580 |
| BS 3S62 | BS 970; 420S37 / 420S29 / 420S45 |
| EN56B / EN56C / EN56D | WS 1.3541 |
| WS 1.4024 | WS 1.4028 |
| AFNOR Z20C13 | UNS S42000 |