Matched ring and pinion gear sets cut on 5-axis centers, heat treated, lapped as a pair, and inspected to ±0.005 mm. We handle the tooth geometry, the mounting distance, and the backlash that decides whether the set runs quiet or howls.
Most ring pinion problems are not visible on the bench. They surface at 60 km/h or after 200 hours under load.
A set that whines between 60 and 90 km/h usually has a tooth contact pattern sitting too high on the heel or too far toward the toe. It passes a bench spin test and fails on the road. Re-cutting the pattern costs a second setup and a second heat treat batch.
Distortion during quenching moves the mounting distance. If the set was cut with backlash at the tight end of the range, the case-hardened parts come back with zero clearance and scuff on the first loaded run. A few hundredths of a millimeter decides this.
This points at case depth or core hardness. A shallow case flexes under load and the flank fatigues. Too deep and the tooth turns brittle. The right depth depends on module, torque, and the surface finish left by the finishing pass.
When the ring and pinion are cut on separate setups without a matched pair record, the second batch will not hold the same pattern as the first. Service replacements then need re-shimming on every install. That is a warranty cost, not a machining cost.
A ring pinion set is not two gears. It is one matched assembly, and we treat the process that way from the first operation.
Spiral bevel and hypoid geometry needs a machine that can hold a precise angle between the cutter and the work axis. We cut these on our 5-axis machining centers and confirm the contact pattern on a lapping machine before the parts leave the cell.
For straight bevel and spur ring pinion sets we use hobbing and shaping, then finish the flanks on a gear grinder when the drawing calls for a tighter lead or profile. The finishing operation is chosen from the tolerance on the tooth flank, not from habit.
Carburizing and case hardening run in-house, followed by induction hardening on the shaft where the bearing journal needs a different hardness than the tooth. We measure case depth on a sectioned coupon from the same batch, so the number on the report belongs to your parts.
After hardening, the ring and pinion go back on the lapping machine as a pair. We adjust the mounting distance and the backlash together, read the pattern in marking compound, and record the numbers. That record is what lets a replacement set drop into the same housing without re-shimming.
Pick the row that matches your volume and tolerance. The last column is the trade-off you are accepting.
| Route | Best for | Typical lead time | Trade-off |
|---|---|---|---|
| Hobbing + shaping | Straight bevel, spur, low to mid volume | 3–5 days after drawing sign-off | No flank grinding, wider lead variation |
| Hobbing + gear grinding | Tight profile or lead on the flank | Adds a setup per batch | Higher cost per part at low volume |
| 5-axis cutting + lapping | Spiral bevel and hypoid axle sets | Set-up driven, quoted per job | Needs a matched lapping step |
| Prototype single set | Fit checks and pattern verification | Quoted per drawing | Not a production price point |
| Production runs | Automotive and industrial axle programs | Scheduled to your release | Requires frozen drawing and fixture |
A ring pinion set rarely ships alone. These are the operations we run in the same plant.
Complex gear blanks, carriers, and differential housings cut in one setup where the geometry allows it. Sixteen simultaneous 5-axis centers, Ø400 mm rotary table.
Shaft turning, spline milling, and bearing journal finishing. Mill-turn centers keep the pinion shaft coaxial with the gear head.
Hobbing, shaping, and grinding for spur, helical, bevel, worm, and ring pinion sets, plus flywheels and flexplate assemblies.
Carburizing, case hardening, and induction hardening, with case depth verified on a sectioned sample from the same lot.
Black oxide, phosphate, bead blasting, and plating on non-critical surfaces. Laser marking at 1.5 mm minimum character height for traceability.
100% inspection before shipment. Contact pattern, backlash, and hardness data recorded and issued with the set on request.
| Item | Range | Notes |
|---|---|---|
| Maximum part size | 4,000 mm | Larger sets quoted case by case |
| Tolerance | ±0.005 mm | Position and mounting distance |
| Tooth flank finish | Ra 0.8–1.6 μm | After grinding, active flank |
| Materials | 4140, 4340, 8620-type, 17-4PH | Case-hardening grades and stainless |
| MOQ | No minimum | One prototype to 10,000+ part runs |
| Quote turnaround | Within 12 hours | Includes free DFM analysis |
Numbers we can stand behind on a ring pinion set order.
Fifteen years of cutting, hardening, and lapping gears in Dongguan, with a second plant in Singapore for regional supply.
Mounting distance and position held to ±0.005 mm (±0.0002 in) on the finished set, checked with the backlash record before shipment.
Raw material check, in-process monitoring, and final inspection. Every set is inspected before it ships, and reports go out on request.
Send a drawing and we return a quotation with a free DFM analysis within 12 hours. Production can start within 24 hours of sign-off.
ISO 9001:2015, IATF 16949:2016, ISO 13485:2016, and ISO 27001:2022 cover the quality system and the handling of your drawings.
Historical late-delivery probability below 2%. Parts ship in 3–5 days on standard jobs, with NDA available on request.
Axle and differential sets that must hold a quiet contact pattern across the whole speed range, with a matched pair record for line-side assembly.
Bevel sets for reducers and drives that run continuously. Case depth is set from the torque curve, not a default, because pitting shows up at 2,000 hours, not 20.
Low-volume and spare-part sets where interchangeability matters. We keep the lapping record so a replacement set drops into the same housing.
Yes. We cut both parts, harden them, then lap them together and record the backlash and mounting distance. The set ships as one unit with those numbers.
If you only need one of the two as a replacement, send the existing mate's marking so we can cut to the same pattern rather than guessing.
A 2D drawing with module or diametral pitch, tooth count, pressure angle, spiral direction, and the mounting distance. A 3D model helps for the blank and the shaft.
If the geometry is not fully defined, tell us the housing, the load, and the ratio. We will run the DFM analysis and come back with a cuttable specification.
Case hardening does move the part. We plan for it: the green cut leaves stock for the finishing pass, and the mounting distance is set after heat treatment, not before.
Case depth is confirmed on a sectioned sample from the same heat lot, so the report reflects your parts.
Ra 0.8–1.6 μm on the active flank after grinding. We can push finer on a specific surface if the drawing calls for it, but that is quoted per job.
As-machined flanks land around Ra 1.6–3.2 μm and are usually fine for low-speed or lightly loaded sets.
Case-hardening alloys such as 4140, 4340, and 8620-type grades, plus 17-4PH stainless where corrosion resistance matters. Other grades from the shop list are available on request.
Material choice follows the load and the environment. Tell us the torque and whether the set sees salt or washdown, and we will recommend one.
There is no minimum order quantity. We run from one prototype to 10,000+ part runs.
Prototype sets are quoted at a different price point than production because of the setup and lapping time. That is normal for gear work.
Uploads are secure and confidential. We can sign an NDA before you send files, and our ISO 27001:2022 system covers how those files are stored and accessed.
We do not share customer drawings or part numbers, and we do not publish customer names.
Yes, if we can get the tooth data. Send the marking on the existing set, the housing, or a worn part plus the ratio and we will reverse the geometry.
We will confirm the contact pattern on a lapping machine before shipping so the replacement runs against the same housing.
Quotation and free DFM analysis within 12 hours. No minimum order quantity, from one prototype set to a 10,000+ part release.
12-hour quote100% inspectionNo MOQNDA on request
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