AISI 4140 Alloy Steel | 1.7225 | SCM440 | 42CrMo4
AISI 4140 Alloy steel material stockholders and suppliers from China-OTAI SPECIAL STEEL . we have more 16 years experience in 4140 steel plate, round bar, flat bar, square supply.AISI 4140 alloy steel is chromium, molybdenum, manganese containing low alloy steel. It has high fatigue strength, abrasion and impact resistance, toughness, and torsional strength. The following datasheet gives an overview of AISI 4140 alloy steel.
4140 alloy steel material is a high quality Quenched and Tempered Alloy Structural steel, It belong to the high quality medium carbon alloy steel, Oil Quenched & Tempered Hardenss is 28-34 HRC.4140 Annealing delivery hardenss less than 250HB.
Related Specifications ASTM A29/A29M DIN EN 10083/3 JIS G4053 GB GB/T 3077
1. SAE AISI 4140 steel Form of Supply
ASTM / AISI 4140 Alloy structural steel, we can supply the round bar, steel flat bar, plate, hexagonal steel bar and square, block. 4140 alloy steel Round bar can be cut to your required lengths as one offs or multiple cut pieces. Rectangular pieces can be cut from flat bar or plate to your specific sizes. Ground tool steel bar can be supply, providing a quality precision finished bar to tight tolerances.
2. AISI 4140 equivalent material
- ♦JAPAN♦ : JIS SCM440 alloy steel
- ♦GERMANY♦ : DIN WN-r 1.7255 / 42CrMo4 steel alloy
- ♦CHINA♦ : GB 42CrMo steel
- ♦BRITISH♦ : BS 708M40
3. AISI 4140 alloy steel Chemical composition
| ASTM A29/29M | C | Si | Mn | Cr | Mo | P | S |
| 4140 | 0.38～0.43 | 0.15～0.35 | 0.75～1.00 | 0.80～1.10 | 0.15～0.25 | ≤0.035 | ≤0.040 |
| DIN WN-r | C | Si | Mn | Cr | Mo | P | S |
| 1.7225 | 0.38～0.45 | ≤0.40 | 0.60～0.90 | 0.90～1.20 | 0.15～0.30 | ≤0.035 | ≤0.035 |
| GB/T | C | Si | Mn | Cr | Mo | P | S |
| 42CrMo | 0.38～0.45 | 0.17～0.37 | 0.50～0.80 | 0.90～1.20 | 0.15～0.25 | ≤0.030 | ≤0.030 |
| BS | C | Si | Mn | Cr | Mo | P | S |
| 708M40 | 0.36～0.44 | 0.10～0.35 | 0.70～1.00 | 0.90～1.20 | 0.15～0.25 | ≤0.035 | ≤0.035 |
| JIS | C | Si | Mn | Cr | Mo | P | S |
| SCM440 | 0.38～0.43 | 0.15～0.35 | 0.60～0.85 | 0.90～1.20 | 0.15～0.30 | ≤0.030 | ≤0.030 |
4. Applications
DIN 4140 Tool steel is a alloy structural steel, 4140 is used for engineering structural, like high tensile shafts, bolts and nuts, gears, pinions and spindles. Locomotive traction with the big gear, supercharger drive gear, pressure vessel, rear axle, gear load of connecting rod and a spring clip,4140 can also be used to under 2000 m deep well of oil drill pipe joint and the fishing tool, and can be used for bending machine mould, etc
5. Supply Size range
Hot Rolled 4140 steel bar: Ø5mm-200mm
Forging 4140 steel bar: Ø140mm-3000mm
Hot rolled 4140 steel plate: Thickness 10mm-200mm x width 100-2300mm
Forged 4140 material steel plate: Thickness 150-1500mm x Width 100 x 3000mm
Others 4140 material have not specified size, pls contact our experienced sales team.
6. 4140 alloy steel Heat treatment
- Annealing
AISI 4140 alloy steel is annealed at 872°C (1600°F) followed by slowly cooling in the furnace. - Tempering
AISI 4140 alloy steel can be tempered at 205 to 649°C (400 to 1200°F) depending upon the desired hardness level. The hardness of the steel can be increased if it has lower tempering temperature. For example, tensile strength of 225 ksi cab be achieved by tempering at 316°C (600°F), and a tensile strength of 130 ksi can be achieved by tempering at 538°C (1000°F). - Hardening
AISI 4140 alloy steel can be hardened by cold working, or heating and quenching.
Mechanical Properties of 4140 alloy steel
| Properties | Metric | Imperial |
| 1.Tensile strength | 655 MPa | 95000 psi |
| 2.Yield strength | 415 MPa | 60200 psi |
| 3.Bulk modulus (typical for steel) | 140 GPa | 20300 ksi |
| 4.Shear modulus (typical for steel) | 80 GPa | 11600 ksi |
| 5.Elastic modulus | 190-210 GPa | 27557-30458 ksi |
| 6.Poisson’s ratio | 0.27-0.30 | 0.27-0.30 |
| 7.Elongation at break (in 50 mm) | 25.70% | 25.70% |
| 8.Hardness, Brinell | 197 | 197 |
| 9.Hardness, Knoop (converted from Brinell hardness) | 219 | 219 |
| 10.Hardness, Rockwell B (converted from Brinell hardness) | 92 | |
| 11.Hardness, Rockwell C (converted from Brinell hardness. Value below normal HRC range, for comparison purposes only) | 13 | 13 |
| 12.Hardness, Vickers (converted from Brinell hardness) | 207 | 207 |
| 13.Machinability (based on AISI 1212 as 100 machinability) | 65 | 65 |
7. Forming
AISI 4140 alloy steel has high ductility. It can be formed using conventional techniques in the annealed condition. It requires more pressure or force for forming because it is tougher than plain carbon steels.
8. Welding
AISI 4140 alloy steel can be welded using all conventional techniques. However, the mechanical properties of this steel will be affected if it is welded in the heat treated condition, and post weld heat treatment should be performed.
9. Forging
AISI 4140 alloy steel is forged at 926 to 1205°C (1700 to 2200°F)
10.Hot Working
AISI 4140 alloy steel can be hot worked at 816 to 1038°C (1500 to 1900°F)
11.Cold Working
AISI 4140 alloy steel can be cold worked using conventional methods in the annealed condition.
12. Processing
AISI 4140 steel round bar and flat sections can be cut to your required sizes. ASTM 4140 tool steel ground bar can also be supplied, providing a high quality tool steel precision ground tool steel bar to your required tolerances. SAE 4140 steel is also available as Ground Flat Stock / Gauge Plate, in standard and nonstandard sizes.
