AISI 4340 | |
Category | Steel |
Class | Alloy steel |
Type | Standard |
Common Names | Nickel-chromium-molybdenum steel |
Designations |
Germany: DIN 1.6565 Japan: JIS SNCM 8 United Kingdom: B.S. 2 S 119 , B.S. 3 S 95 , B.S. 3111 Type 6 , B.S. 817 M 40 United States: AMS 5331 , AMS 6359 , AMS 6359B , AMS 6414 , AMS 6414A , AMS 6415 , AMS 6415G , ASTM A322 , ASTM A331 , ASTM A505 , ASTM A519 , ASTM A547 , ASTM A646 , MIL SPEC MIL-S-16974 , SAE J404 , SAE J412 , SAE J770 , UNS G43400 |
Composition | |
Element | Weight % |
C | 0.38-0.43 |
Mn | 0.60-0.80 |
P | 0.035 (max) |
S | 0.04 (max) |
Si | 0.15-0.30 |
Cr | 0.70-0.90 |
Ni | 1.65-2.00 |
Mo | 0.20-0.30 |
Mechanical Properties | |
Properties | Conditions | ||
T (°C) | Treatment | ||
Density (×1000 kg/m3) | 7.7-8.03 | 25 | |
Poisson's Ratio | 0.27-0.30 | 25 | |
Elastic Modulus (GPa) | 190-210 | 25 | |
Tensile Strength (Mpa) | 744.6 | 25 | annealed at 810°C more |
Yield Strength (Mpa) | 472.3 | ||
Elongation (%) | 22.0 | ||
Reduction in Area (%) | 49.9 | ||
Hardness (HB) | 217 | 25 | annealed at 810°C more |
Impact Strength (J) (Izod) |
51.1 | 25 | annealed at 810°C more |
Thermal Properties | |
Properties | Conditions | ||
T (°C) | Treatment | ||
Thermal Expansion (10-6/ºC) | 11.5 | 20-100 more | oil hardened, tempered 630°C |
Electric Properties | |