Precision Turned 20CrMnTi Steel Differential Pinion Shaft HRC 58 Carburized 35mm Shaft Diameter

This differential pinion shaft is machined from Alloy Steel 20CrMnTi (20CrMnTi carburizing grade) to ±0.012mm in the critical dimensions, then finished by Carburized HRC 58-62 ground journals. It is produced on CNC turning centres that are dedicated to small and medium volume precision work, so every dimension on the drawing is generated by the machine rather than by hand fitting. Typical users are engineers who have already been let down by a supplier that quoted a tolerance it could not hold, and who need the part to fit the first time without sorting or rework on the assembly line.

• Deep Case For High Contact Stress: 1.0 to 1.4mm case depth at HRC 58-62 supports the high hertzian stress of a hypoid pinion
• Ground Bearing Journals: Journals are ground after heat treat to k6 tolerance for correct bearing interference fit
• Controlled Core Toughness: Core remains at HRC 32-38 so the shaft absorbs torque spikes without tooth breakage
• Gear Teeth Cut After Soft Stage: Teeth are cut while soft then hardened in a controlled atmosphere furnace for predictable distortion
• Runout Verified On Gear Checker: Gear runout and tooth thickness are measured and reported per lot

The process route is fixed before metal is cut. Bar stock is verified against the purchase specification and the heat number is logged, then a first article is turned and measured in full. Only after the first article is signed off does the lot run. Critical features on this differential pinion shaft are controlled to ±0.012mm with a process capability target of Cpk 1.33 or better, and the operator checks the feature at a defined frequency with the gauge stated on the control plan. Where the drawing calls for Carburized HRC 58-62 ground journals, the finishing step is carried out in house and the result is measured, not assumed. Sample parts go to the CMM for full dimensional verification, and the recorded results ship with the lot as a first article inspection report in PPAP level 3 format when a customer program requires it.

Questions are handled by engineers rather than by sales staff. Our team reviews each drawing for manufacturability, flags features that would drive cost without adding function, and proposes the tolerance band that actually matters for the assembly. That review is free and is returned within 24 hours together with a quotation. When a part fails in the field, we ask for the sample back, section it if needed and report what the failure mechanism was, because a supplier that cannot explain a failure cannot prevent the next one.

• Machines: 50+ CNC units including Swiss type lathes, 3, 4 and 5 axis machining centres and turn-mill centres from Citizen, Star, Doosan and Mazak.
• Quality lab: CMM, 2D vision measurement, roughness tester, hardness tester, salt spray chamber and spectral analyser for material verification.
• Team: 15+ mechanical engineers covering DFM review, process design, fixture design and failure analysis.
• Capacity: 500,000+ precision turned parts per month with stable output and on time delivery tracking.
• Quality system: ISO 9001:2015 certified, SGS audited, material traceability from mill heat to finished part.
• Export experience: parts shipped to 30+ countries across North America, Europe, Japan, Korea and Southeast Asia.

Automotive differentials, off highway axle drives, electric forklift transmissions and agricultural gearboxes.

Parts are degreased, dried and packed so that the surface finish specified above arrives intact. Standard packing is VCI paper or individual PE bag, a partitioned foam tray for form features, and an export grade corrugated carton on a pallet, with the lot number and heat number marked on the outside. Parts are warranted against material and workmanship defects for 12 months from delivery. If a part is found outside the drawing, we replace it at our cost and we pay the return freight for the defective lot. Third party inspection by SGS, BV or TUV can be arranged before shipment at your request, and we work under NDA where drawings are confidential.

Q: Can you supply a matched ring and pinion set? A: We machine the pinion shaft and can source or machine a matched ring gear. If you need a lapped pair, tell us the ratio and backlash target.

Q: How do you prevent heat treat distortion on a pinion shaft? A: The shaft is press quenched on a dedicated fixture and finished before hardening by leaving grinding stock. Journals are ground after heat treat, which removes distortion.

Q: What gear geometry data do you need to quote? A: Module, number of teeth, pressure angle, helix angle, profile shift and the mating gear data. A sample part also works and we will reverse the geometry and send it for your approval.

Q: Do you provide PPAP documentation? A: Yes, PPAP level 3 with dimensional results, material certificates, heat treat records and control plan is available for automotive programs.

Q: How do you confirm the Alloy Steel 20CrMnTi material before it is machined? A: Every bar is checked against its mill certificate with an optical emission spectrometer before it goes to a machine. If the chemistry does not match the grade, the bar is rejected and returned. The certificate for your lot is filed under the heat number and can be sent with the shipment or on request.

Q: What happens if a delivered part measures outside the ±0.012mm tolerance? A: Send the measurement and the lot number. We check the recorded values for that lot, replace the parts at our cost and cover the return freight. Because each critical feature is recorded during production, we can trace the deviation to a tool wear step, a fixture shift or a gauge issue and correct the process before the next lot runs.

Send a 2D drawing, a STEP file or a sample and you will have a manufacturability review and a firm quotation within 24 hours. Trial orders from a single piece are accepted, so the tolerance claim can be checked on your own assembly before a production order is placed.