| Specification | Detail |
|---|---|
| Material | 42CrMo4 (AISI 4140), 34CrNiMo6, 35CrMo, 45 carbon steel |
| Process | Silica sol investment casting plus CNC rough and finish turning, near net shape ring blank |
| Tolerance | ISO 8062 CT7 to CT8 as cast, +/-0.05 mm on machined datum and bolt faces |
| Surface finish | Ra 3.2 to 6.3 micrometer machined, shot blasted as cast surfaces |
| Weight range | 8 kg to 450 kg per ring |
| Heat treatment | Normalizing, quench and temper to 28 to 32 HRC, optional pre-machining for induction hardening |
| Inspection | CMM dimensional report, ultrasonic testing to EN 10228-3, hardness mapping, magnetic particle inspection of root zone |
Key features
- Near net shape ring casting cuts raw material buy-to-fly ratio and shortens gear cutting cycle time.
- Homogeneous quenched and tempered microstructure with controlled grain flow for tooth root fatigue strength.
- Machined datum faces and bolt hole circle delivered ready for hobbing, shaping or grinding.
- Wall thickness control across the ring section prevents distortion during hardening.
- Optional cast-in lifting lugs, grease grooves and seal seat recesses to remove secondary operations.
- Supplied as single blanks, split rings or matched sets with serialized traceability.
- Compatible with external and internal gear cutting for single and double row slewing bearings.
Applications
- Excavator swing circle and upperstructure slewing bearings.
- Crawler crane and mobile crane slewing rings.
- Aerial work platform and telescopic handler turntables.
- Rotary drilling rigs and pile driving rig rotary tables.
- Forestry cranes, knuckle boom loaders and material handlers.
- Wind turbine yaw and pitch bearing rings.
Quality and compliance
Every slew ring gear blank is produced under an IATF 16949 certified quality system, with full heat lot traceability and an EN 10204 3.1 material certificate issued for each batch. First-article inspection reports including dimensional layout, mechanical properties and NDT results are submitted for approval before series release. Process capability studies on critical diameters and bolt circle positions are available on request.
FAQ
Q: Can you supply the ring fully gear cut?
A: We deliver rough or pre-machined blanks for our customers to cut the teeth, and we can also subcontract hobbing and grinding with controlled partners when the drawing requires finished gearing.
Q: What is your maximum ring diameter?
A: Investment cast rings are routinely produced up to 1200 mm outside diameter, and larger sizes can be quoted by splitting the ring into segments with machined joint faces.
Q: How do you control distortion before heat treatment?
A: We use symmetric gating, controlled cooling in the shell and a rough machining allowance that is verified after quench and temper, so the final machining removes any heat treatment movement.
Q: Do you provide material certificates with every shipment?
A: Yes, EN 10204 3.1 certificates with heat number, chemical analysis and mechanical test results are issued for every production lot as standard.
Q: What information do you need for a quotation?
A: Send the drawing or sample, target steel grade, required hardness, annual volume and any NDT specification, and we will return a tooling and piece price within three working days.
