High-strength alloy quenched and tempered steel for demanding applications
Steel grade 1.7225 (42CrMo4) is one of the most widely used alloy quenched and tempered steels. It is characterized by high strength, excellent toughness, good hardenability, and outstanding resistance to fatigue stress.
It is mainly used for components exposed to high loads, impact stress, compressive stress, and wherever long service life is required.
Properties of steel 1.7225 (42CrMo4)
🔩 High strength after quenching and tempering
The tensile strength Rm can reach 900–1100 MPa while the steel retains its toughness.
⚙️ Excellent hardenability and uniform structure
Thanks to chromium and molybdenum, the steel hardens well even in larger diameters, making it suitable for large components.
🔧 Good machinability in the annealed condition
In delivery condition +A or +N, the steel machines very well and is suitable for precise components.
🔥 High resistance to fatigue and impact loading
Ideal for rotating parts, highly loaded shafts, and precision engineering components.
🛠️ Possibility of surface hardening
An induction-hardened surface can achieve a hardness of 52–57 HRC.
Chemical composition 1.7225 (42CrMo4)
| Element | Content (%) |
|---|---|
| C | 0.38 – 0.45 |
| Cr | 0.90 – 1.20 |
| Mo | 0.15 – 0.30 |
| Mn | 0.60 – 0.90 |
| Si | 0.10 – 0.40 |
| P | ≤ 0.025 |
| S | ≤ 0.035 |
Typical applications of steel 1.7225
⚙️ Automotive industry
shafts, transmission shafts
gears
axles, clutch components
piston rods and pins
🏭 Heavy engineering
spindles, pins, tie rods
highly loaded bolts and nuts
hydraulic components
🔩 Energy sector and heavily loaded machinery
turbine parts
pressure-loaded components
components operating under fatigue conditions
Heat treatment (guideline values)
| Process | Temperature | Note |
|---|---|---|
| Quenching and tempering | 830 – 870 °C hardening → 540 – 680 °C tempering | goal: strength + toughness |
| Hardening | 830 – 870 °C | oil quenching |
| Tempering | 540 – 680 °C | depending on the required strength |
| Induction hardening | 800 – 860 °C | surface hardness 52–57 HRC |
| Soft annealing | 650 – 700 °C | improved machinability |
Mechanical properties
Tensile strength Rm: 900–1100 MPa (after quenching and tempering)
Yield strength Re: 700–900 MPa
Core hardness (HB): 200–300 HB, depending on the condition
Surface hardness after induction hardening: 52–57 HRC
Elongation A: 10–14 %
