CNC Turned 1045 Carbon Steel Splined Hub 40mm Bore 20 Teeth HRC 28 Custom

This splined hub is machined from Carbon Steel 1045 (1045 quenched and tempered) to ±0.015mm in the critical dimensions, then finished by Black oxide HRC 28-32. 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.

• Concentric Bore And Spline: 0.02mm concentricity between bore and spline reduces vibration and evens load across the teeth
• Through Hardened Body: HRC 28-32 supports 2,400 Nm torque while keeping the hub machinable for keyway and set screws
• Black Oxide Finish: Black oxide protects against handling corrosion and holds a light oil film on the spline
• Bore Sized For Interference Fit: Bore is held to H7 with a stated installed clearance for the mating shaft class you specify
• Spline Inspected With Gauges: Spline is checked with GO and NO-GO gauges and tooth thickness readings 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 splined hub are controlled to ±0.015mm 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 Black oxide HRC 28-32, 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.

Power transmission couplings, agricultural implement drives, conveyor gearbox hubs and industrial machinery driveshafts.

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: Should the hub be hardened after spline cutting? A: For 1045 at this hardness we cut the spline after hardening and tempering, which avoids the distortion that comes from hardening a finished spline.

Q: Can you machine a keyway as well as the spline? A: Yes, but normally a hub has either a spline or a keyway, not both. If you need both, we machine the keyway in a separate setup and check the angular relationship.

Q: What spline standard do you work to? A: We work to ANSI B92.1, DIN 5480, DIN 5482 and Japanese standards. Send the standard and fit class and we will confirm the tooth geometry.

Q: Do you offer a hardened version for higher torque? A: Yes, we can supply through hardened 4140 or a carburized version if the torque exceeds what 1045 will carry.

Q: How do you confirm the Carbon Steel 1045 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 ±0.015mm 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.