What is Grade 4140?
Grade 4140 is a chromium-molybdenum alloy steel that has excellent hardenability and good fatigue strength. This 4140 tube has higher carbon content than 4130. This higher amount of carbon provides greater strength when heat-treated. The alloy responds well to flame and induction hardening for surface hardening applications. This makes it suitable for components requiring a hard and wear-resistant surface with a tough core.
ASTM A519 Grade 4140 Tube Specification
The technical specifications for ASTM A519 Grade 4140 Carbon steel alloy tubing are as given below:
| Dimensions | ASTM, ASME and API |
|---|---|
| Supplier of 4140 Alloy Steel Tube in Length | Within 13500 millimeter |
| Speciality in | Large Diameter Size |
| Size | 4 to 219 millimeter W. T.: 0.5 to 20 millimeter |
| Length | In Single and Double Random & Cut to Length Suppliers |
| AISI 4140 Tube Type | Welded / Seamless / Fabricated / ERW |
| Form | Round, Square, Rectangular, Hydraulic. |
| End | Plain End, Threaded, Beveled End |
ASTM A519 Grade 4140 Tube Chemical Composition
The table below provides the chemical composition of AISI 4140 steel tubing per ASTM A519:
| Standard | Grade | C | Mn | P | S | Si | Ni | Cr | Mo |
|---|---|---|---|---|---|---|---|---|---|
| ASTM A29 | 4140 | 0.38-0.43 | 0.75-1.00 | 0.035 | 0.040 | 0.15-0.35 | – | 0.8-1.10 | 0.15-0.25 |
| EN 10250 | 42CrMo4 / 1.7224 | 0.38-0.45 | 0.6-0.9 | 0.035 | 0.035 | 0.4 | – | 0.9-1.2 | 0.15-0.30 |
| JIS G4105 | SCM440 | 0.38-0.43 | 0.60-0.85 | 0.03 | 0.03 | 0.15-0.35 | – | 0.9-1.2 | 0.15-0.30 |
ASTM A519 Grade 4140 Tube Mechanical Properties
AISI 4140 steel tubing achieves superior strength and hardness through heat treatment. Its mechanical properties are outlined in the table below:
| Properties | Metric | Imperial |
|---|---|---|
| Hardness, Vickers (converted from Brinell hardness) | 207 | 207 |
| Tensile strength | 655 MPa | 95000 psi |
| Bulk modulus (typical for steel) | 140 GPa | 20300 ksi |
| Yield strength | 415 MPa | 60200 psi |
| Hardness, Rockwell C (converted from Brinell hardness, value below normal HRC range, for comparison only) | 13 | 13 |
| Elastic modulus | 190-210 GPa | 27557-30458 ksi |
| Poisson’s ratio | 0.27-0.30 | 0.27-0.30 |
| Elongation at break (in 50 mm) | 25.70% | 25.70% |
| Shear modulus (typical for steel) | 80 GPa | 11600 ksi |
| Hardness, Brinell | 197 | 197 |
| Machinability (based on AISI 1212 as 100 machinability) | 65 | 65 |
| Hardness, Rockwell B (converted from Brinell hardness) | 92 | 92 |
| Hardness, Knoop (converted from Brinell hardness) | 219 | 219 |
Heat Treatment
The following heat treatment capabilities are available for AISI 4140 heat treated steel tubing:
- Annealed: HB 197 max
- Quenched & Tempered: HRC 28-32 typical
- Surface Hardening: Flame or induction hardening possible for wear surfaces
Applications
The 4140 seamless tubing serves the following 2 high-strength applications: