42CrMo4 (EN 1.7225) / ASTM 4140 is a core quenched and tempered alloy steel round bar grade with high strength, good toughness, and excellent fatigue resistance.
42CrMo4 / ASTM 4140
QT alloy steel round bar for high-load hydraulic and rotating parts.
This grade combines strength, toughness, and fatigue resistance, which is why it is commonly used for critical components in hydraulic systems, wind power equipment, and marine applications.
Key point
Stable QT performance with flexible machining support.
Suitable for rods, shafts, flanges, gears, and other heavy-duty parts.
Product Summary
Technical data buyers normally request first.
The summary below normalizes the original product note into a clean procurement format.
| EN | 42CrMo4 / 1.7225 |
|---|---|
| ASTM | A29 / A322 - 4140 |
| DIN | 42CrMo4 |
| JIS | SCM440 |
| GB | 42CrMo |
| C | 0.38 - 0.45 |
|---|---|
| Si | 0.15 - 0.40 |
| Mn | 0.60 - 0.90 |
| Cr | 0.90 - 1.20 |
| Mo | 0.15 - 0.30 |
| Tensile strength | 850 - 1000 MPa |
|---|---|
| Yield strength | ≥ 650 MPa |
| Elongation | ≥ 13% |
| Impact toughness | Good at room temperature |
| Form | Round bar |
|---|---|
| Diameter | 20 - 400 mm |
| Length | 3 - 12 m |
| Condition | Quenched and tempered (QT) |
| Surface | Black / Peeled / Machined |
- Hydraulic cylinder rods and piston rods
- Wind power shafts and flanges
- Marine drive shafts and coupling components
- Heavy-duty gears, spindles, and mechanical shafts
- Hot rolled and forged bars
- Customized QT heat treatment
- Rough machining and precision machining
- Surface treatments upon request
- Chemical composition analysis
- Mechanical testing
- Ultrasonic testing (UT)
- Dimensional inspection and third-party inspection available
Inquiry
Need 42CrMo4 availability or pricing?
Share size, quantity, delivery condition, and destination for a quick response.