| AISI A4 | |
![]() | |
| Category | Steel |
| Class | Tool steel |
| Type | Air-hardening medium-alloy cold work steel |
| Designations | United States: ASTM A681 , FED QQ-T-570 , UNS T30104 |
| Composition | |
![]() | |
| Element | Weight % |
| C | 0.95-1.05 |
| Mn | 1.80-2.20 |
| Si | 0.50 |
| Cr | 0.90-2.20 |
| Ni | 0.30 |
| Mo | 0.90-1.40 |
| Cu | 0.25 |
| P | 0.03 |
| S | 0.03 |
| Mechanical Properties | |
![]() | |
















