Large Diameter Precision Quenched Ring Gear for Machinery

Large diameter precision ring gear

This product is a critical rotating-drive component: a quenched-and-tempered tough core, an induction-hardened wear-resistant case on the external teeth, and precision gear grinding that removes hardening distortion and restores/improves tooth accuracy. It is essentially a "hardened-face large ring gear", integrating the external ring of a large slewing bearing with the slew-drive gear (bull gear). Such hardened-face large ring gears are widely used in low-speed heavy-duty, frequently slewing, and precisely indexing equipment.

Features & performance advantages

Integrally forged 42CrMo (GB/T 3077), equivalent to 42CrMo4 / 1.7225 / AISI 4140 / SCM440, with balanced hardenability, strength and toughness.

MF/HF induction hardening of external teeth + low-temperature tempering; 50–62 HRC; case depth designed at 0.2–0.4× module for pitting, wear and bending-fatigue resistance.

Precision grinding after hardening achieves GB/T 10095 Grade 6 or higher with Ra ≤ 0.4 μm, ensuring smooth, low-noise, long-life meshing under low-speed heavy-duty service.

Specification

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Why Choose Us

High load capacity, wear resistance & long service life

Strict dimensional tolerance, smooth rotation

Customization drawings / OEM / ODM available

Direct factory price, stable delivery

Complete inspection & test report before shipment

Suitable for heavy-duty engineering & harsh working environment

After Sales Service

Tailored product according to your drawings or samples

Professional technical support anytime

Strict quality inspection & full set of shipping documents

Fast delivery & safe packaging (plywood pallet/case)

One-year quality warranty

FAQ

1.  Why choose 42CrMo as the material of ring gear?

Cr-Mo alloying gives consistent through-hardening even in large sections (wall thickness up to several hundred mm), ideal for large diameter ring gears. Good hardenability and moderate Ms point allow better control of roundness and runout after induction hardening than plain carbon steels (e.g. 45# or 50Mn). Rm ≥ 1080 MPa after Q&T with excellent impact toughness, suited to heavy-load, impact and frequent start-stop slewing duty. Medium-carbon Cr steel responds well to induction hardening, stably reaching 50–62 HRC without carburizing, keeping cost controlled.

2. What is the core performance of this ring gear?

The gradient structure of "hard case + tough core" is the core performance logic of this product. Too shallow a case risks pitting/spalling; too deep increases brittleness — matching case depth to module and duty is the design key. Wear/pitting-resistant flank with impact/fracture-resistant core — reconciling hardness and toughness.

*For technical consultation or custom quotations, please provide gear parameters (module, number of teeth, face width, accuracy requirements, operating conditions, etc.). Our engineering team will deliver a professional solution tailored to your specific needs.