Case-hardening steels are special alloy steels with low carbon content that gain high wear resistance and impact strength through a surface-hardening process (carburising). In these steels the surface layer becomes very hard while the core remains tough and resilient. This provides both high load-bearing capacity and long service life, enabling the parts to carry heavy loads and withstand impact-type loading. In addition to gears, case-hardening steels should be used where high wear and fatigue resistance is required — machined shafts, pistons, chain links, discs, guides and bearing housings.

Key Properties

• High surface hardness
• Excellent wear resistance
• High resistance to impact and fatigue
• Tough, durable core
• Long service life
• Superior mechanical properties after surface hardening such as carburising, nitriding and carbonitriding

Applications

Case-hardening steels are especially preferred for machine parts used in machine parts subject to high wear and heavy loads:

• Automotive gears
• Gearbox (transmission) parts
• Differential gears
• Sprockets
• Shafts and axles
• Camshafts
• Bearing parts
• Industrial machinery equipment

Advantages

Through case hardening, the outer surfaces of parts can reach 58–62 HRC while the core remains flexible and tough. This reduces the risk of fracture — particularly in gears and power-transmission elements — while significantly extending service life.

Case-hardening steels are among the indispensable materials for engineering applications demanding high performance, long life and reliability.