Project Overview

Singapore’s urban construction and port lifting projects are humid, salty, and involve frequent heavy hoisting. For the Kato NK500 large road crane, we developed a custom external-gear slewing ring that meets OEM requirements and handles steady rotation under full loads.

High-strength 42CrMo steel – the inner raceway is quenched and hardness-tested for wear and impact resistance. Precision CNC drilling creates inner mounting holes, and we measure overall height and outer hole spacing to ensure seamless on-site installation. Gear teeth are induction-hardened to DIN Class 7 for smooth meshing under alternating loads.

Multi-layer anti-rust/waterproof sealing and dedicated lubrication channels isolate salt fog and construction dust typical of Singapore’s coastal environment. All dimensions are checked against drawings. Our photo record covers heat treatment, precision measurement, finished packaging, wooden case packing/unpacking, and even real equipment at client sites. Designed for long hoisting tasks, this large ring gives reliable, lasting rotation for Singapore’s urban and port mobile crane projects.

Technical Highlights

  • Custom triple-lip seal design to prevent dust and moisture ingress
  • Induction-hardened raceway: 55–58 HRC surface, 3.5 mm case depth
  • External gear profile: module m=6, Z=168, 20° pressure angle
  • Load capacity: 680 kN axial, 135 kNm overturning moment
  • Grease refill interval extended from 80h to 200h with polyurea-based high-temp grease
  • Pre-assembly ultrasonic inspection and 360° torque test before shipment

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