4140-125 KSI
AISI 4140 is a chromium-molybdenum alloy steel supplied in normalized or quenched and tempered conditions. It offers an excellent combination of strength, toughness, and fatigue resistance.
The alloy is widely used for shafts, gears, forgings, and structural components where high strength and impact resistance are required.
Specifications
- UNS: 641400
- ASTM A29, A322
- EN/DIN: 1.7225
- Structure: Alloy Steel (Cr Moj
- Condition Supplied: Normalized/OST
Data Tables
Chemical Composition:
| Material Grade | ASTM Standard | Desgnation(EN /UNS) | Yield Strength (MPa) | Yield Strength (KSI) | Tensile Strength (MPa) | Tensile Strength (KSI) | Elongation (%) | Reduction of Area (%) | Hardness(HRC/HBWMax) | Condition | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| AISI 4140 (80 KSI) | ASTM A434 /A322 | EN 1.7225(G41400) | 552 | 80.060976 | 655 | 94.99989 | 20 | 45 | 237 HBW | Normalized+ Quenching + Temper | |
| AISI 4140 (110 KSI) | ASTM A434 / A322 | EN 1.7225(G41400) | 758 | 109.938804 | 862 | 125.022756 | 13 | 40 | 285-341 HBW | Normalized+ Quenching + Temper | |
| AISI 4140 (125 KSI) | ASTM A434 / A322 | EN 1.7225(G41400) | 862 | 125.022756 | 965 | 139.96167 | 10 | 35 | 301-353 HBW | Normalized+ Quenching + Temper | |
| AISI 4140 (140 KSI) | ASTM A434 / A322 | EN 1.7225(G41400) | 965 | 139.96167 | 1069 | 155.045622 | 12 | 40 | 336-371 HBW | Normalized+ Quenching + Temper |
Mechanical Properties:
| C | Mn | P | S | Si | Cr | Ni | Ti | Mo | N | Cu | Fe | Co | Nb (+Ta) | V | W | Al | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | 16.5 | 10 | 2 | ||||||||||||||
| Max | 0.04 | 2 | 0.04 | 0.03 | 1 | 18.5 | 13 | 2.5 | 0.11 | Bal |
Physical Properties:
| Material Grade | Density (g/cm³) | Melting Range (°C) | Modulus of Elasticity (GPa) | Thermal Conductivity (W/m·K) | Thermal Expansion (×10⁻⁶ /°C) | Electrical Resistivity (µΩ·m) | Magnetic Behavior |
|---|---|---|---|---|---|---|---|
| AISI 4140 | 7.85 | 1416 | 205 | 42.6 | 12.3 | 0.2 | Magnetic |
Key Features
- High strength and toughness
- Excellent fatigue and impact resistance
- Good hardenability and heat treatment response
- Good machinability in annealed condition
- Widely used engineering alloy steel
Applications
- Forged shafts and axles
- Gears and pinions
- Automotive and machinery components
- Heavy-duty bolts and fasteners
- Structural and mechanical parts