1.6587 / 18CrNiMo7-6 – High-quality case-hardening steel for heavily loaded gears, shafts and transmission components
Steel 1.6587 (18CrNiMo7-6, ČSN 16 255) is one of the highest-quality case-hardening steels for extremely demanding applications. It is specially designed for components that require a very hard, wear-resistant surface together with a tough and durable core.
Thanks to this combination of properties, 18CrNiMo7-6 is an excellent choice for gears, pinions, shafts, transmission parts and rotating precision components exposed to high shock, pressure and cyclic loads over a long service life.
After case hardening, the steel achieves a very high surface hardness while maintaining excellent core toughness. This makes it ideal for safety-critical and highly stressed parts used in mechanical engineering, drive systems, commercial vehicles and the energy sector.
Properties of 1.6587 (18CrNiMo7-6)
🔩 Very high surface hardness after case hardening
After carburizing and hardening, the surface typically reaches 60–63 HRC, providing excellent wear resistance and long service life even under heavy load.
⚙️ Tough and high-strength core
While the surface becomes extremely hard, the core remains tough and resistant to shock and deformation. This combination helps prevent brittle fracture, cracking and distortion.
🔧 Very good hardenability
The steel is also suitable for larger cross-sections and massive parts, as it allows uniform and reliable heat treatment.
🔥 High fatigue and impact resistance
1.6587 is especially suitable for components subjected to dynamic loads, alternating stresses and shock loading.
🛠️ High dimensional stability and process reliability
This material is frequently used where precision, long-term reliability and dependable performance are essential.
Chemical composition
| Element | Content (%) |
|---|---|
| C | 0.15 – 0.21 |
| Cr | 1.50 – 1.80 |
| Ni | 1.40 – 1.70 |
| Mo | 0.25 – 0.35 |
| Mn | 0.50 – 0.90 |
| Si | 0.10 – 0.40 |
| P | ≤ 0.025 |
| S | ≤ 0.035 |
Typical applications
⚙️ Gear and transmission engineering
- gears
- pinions
- transmission shafts
- planetary gear systems
- differential components
🏭 Mechanical engineering and heavy industry
- heavily loaded shafts
- rotors
- spindles
- drive components
🚛 Commercial vehicle and automotive applications
- drive shafts
- gearbox components
- heavily loaded power transmission parts
- components for trucks and working machinery
⚡ Energy and turbine engineering
- turbine components
- highly loaded rotating parts
- precision components for continuous operation
✈️ Aerospace and railway engineering
- safety-critical transmission components
- highly stressed gear systems
- wear-resistant precision parts
Heat treatment (guideline values)
| Process | Temperature | Note |
|---|---|---|
| Carburizing | 880 – 950 °C | case depth approx. 0.8–1.5 mm |
| Hardening after carburizing | 800 – 830 °C | oil |
| Tempering | 150 – 200 °C | target surface hardness 60–63 HRC |
| Core quenching and tempering | 830 – 870 °C + 550 – 650 °C | tough core |
| Soft annealing | 650 – 700 °C | improved machinability |
Mechanical properties
- Surface hardness: 60–63 HRC
- Case depth: approx. 0.8–1.5 mm
- Core tensile strength (Rm): 900–1100 MPa
- Yield strength (Re): 650–850 MPa
- Core hardness: approx. 250–350 HB
- Elongation (A): 10–12%
Delivery condition
Steel 1.6587 / 18CrNiMo7-6 is available in different delivery conditions depending on size and availability. On request, we supply this material cut to size for your further processing.
Why choose 1.6587 from DOBROSTEEL?
At DOBROSTEEL, you get quality steel for demanding technical applications. We supply 1.6587 / 18CrNiMo7-6 with precise cut-to-size processing, fast handling and reliable service for industry, engineering and manufacturing.
