Material selection for a ring gear application depends primarily on the application’s load spectrum, operating environment, and expected service life.
For most industrial and automotive applications requiring surface hardness and wear resistance, we recommend case-carburizing grades such as 20MnCr5, 16MnCr5, 18CrNiMo7-6, or SAE 8620. These materials allow a hard, wear-resistant case (58–62 HRC) with a tough, shock-absorbing core (30–40 HRC).
For large ring gears where distortion during carburizing is a major concern, we recommend nitriding steels like 42CrMo4V or 34CrAlMo5, which can achieve surface hardness (55–60 HRC equivalent) through gas or plasma nitriding at lower temperatures, resulting in minimal distortion.
For low-speed, high-torque applications where through-hardening is acceptable, we use medium-carbon alloy steels such as 42CrMo4 or 4140, quenched and tempered to 280–340 HB.
We can also source specialized materials including stainless steels (for corrosive environments), ductile cast irons (for cost-sensitive large rings), and aerospace-grade superalloys upon request. All materials are supplied with full mill certificates and are traceable to the heat number.