42crmo4 Aisi 4140 42crmo4 4140 Low Alloy Steel 1.7225 Astm Scm440
AISI 4140 Alloy Structural Steel 6.0mm-1200mm Hot Rolled Bright
AISI 4140 steel is Chrome-Moly High Tensile Steel which has at least 0.8%Cr,0.15%Mo as strengthening alloy elements.The chromium content provides good hardness penetration, and the molybdenum content ensures uniform hardness and high strength. AISI 4140 steel can be oil hardened to a relatively high level of hardness with a tensile strength of 850 – 1000 MPa.AISI 4140 offers a very good balance of strength,toughness and wear-resistance.Compared with AISI 4130,it has a slightly higher carbon content which gives greater strength and heat treatment capabilities , however it is poor in weldability.Pre hardened and tempered 4140 can be further surface hardened by flame or induction hardening(can be surface hardened to a typical value 58HRC)and by nitriding( Surface hardness achievable is 600 to 650HV).
Supply Form & Size
| Form of Supply | Size(mm) | Length(mm) |
| Round bar | Φ5-Φ1,200 | 3,000-10,000 |
| Square bar | 100×100-600×600 | 3,000-6,000 |
| Plate/Sheet | Thickness :20-400 Width:80-1,000 |
2,000-6,000 |
| Flat bar/Blcoks | Thickness :120-800 Width:120-1,500 |
2,000-6,000 |
Chemical Composition&Related Specifications
| Grade | C | Si | Mn | P | S | Cr | Mo |
| 4140 | 0.38-0.43 | 0.15-0.35 | 0.75-1.0 | ≤0.035 | ≤0.04 | 0.8-1.1 | 0.15-0.25 |
Brand comparison table
| Germany | AISI/SAE | China | Japan |
| 42CrMo4/1.7225 | 4140 | 42CrMo | SCM440 |
AISI 4140 steel Mechanical Property
| Ruling Section mm | <254 | <127 |
| Tensile Strength Mpa | 690 | 862 |
| Yield Strength Mpa | 552 | 758 |
| Elongation % | >20 | >13 |
| Reduction of Area % | >40 | >40 |
| Charpy Impact -46°C, J | >42 | >27 |
| Hardness HB | 217-235 | 285-341 |
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