We machine bell housings, e-motor housings and gearbox covers from billet or cast blanks. One setup on 5-axis holds bore-to-face alignment, so the input shaft, bearing bores and dowel pins land where the drivetrain drawing says they should.
Most bell housing problems are not surface problems. They are alignment problems that only appear when the gearbox is bolted up.
The bearing bore runs out of true to the mounting face. Input shaft alignment drifts, the pilot bearing loads on one side, and the unit growls at a specific rpm band. A CMM report on the first article catches this before the parts ship.
Holes are reamed in a second setup with a fresh datum. Batch one fits, batch three does not, and the line rejects a whole pallet. Keeping the dowel pattern in the same setup as the bore removes that variable.
Casting shift moves 1.5 mm of stock to one side. A fixed toolpath then cuts through a rib or leaves a thick web that adds mass. We probe the blank first and shift the toolpath to the actual casting.
The mounting face measures flat on the bench, then warps during anodizing or service heat. Stress-relieved stock and a controlled finishing sequence hold the flange flat.
Bore, face, dowel pattern and bolt circle come off the same zero point.
A bell housing has one job: hold the transmission input axis in line with the crankshaft or motor shaft. That relationship lives in the bore-to-face geometry, so we cut the mounting face, the bearing bore, the dowel holes and the bolt circle without breaking the setup. On a Ø400 mm rotary table the part rotates instead of being re-fixtured.
For castings we probe the blank and shift the toolpath to the real surface. That keeps wall thickness even when the casting shifts, and it stops a rib from being cut through. First articles ship with dimensional data so your engineers can check the numbers before the run continues.
Billet suits prototypes and low-volume runs where no tooling exists yet. You get uniform grain, no porosity and full freedom to change wall thickness between revisions. It costs more per part at high volume because every surface is cut from solid.
A die casting pays off once the geometry is frozen and the annual volume is large. The trade is porosity control and draft angles, which we handle by machining the critical bores and faces after casting. Aluminum alloys we run include 6061-T6, 6082, 7075 and ADC12 for cast blanks.
Use this to decide before you send a drawing.
| Condition | Billet machining | Die casting + machining |
|---|---|---|
| Prototype or first revision | Fits well | Tooling cost not justified |
| Annual volume under 500 | Lower total cost | Tooling spread too thin |
| Frozen geometry, 5,000+ /year | Higher per-part cost | Lower per-part cost |
| Wall thickness under 4 mm | Stable, no porosity | Needs draft and rib review |
| Bore tolerance under ±0.01 mm | Machined directly | Machined after casting |
| Design still changing monthly | Change the program | Tooling change is costly |
One supplier for the shell, the mating parts and the finish.
Simultaneous 5-axis for one-setup bore and face work on housings up to 4,000 mm.
Mill-turn centers for flanges, bearing caps and shaft-side features in one cycle.
Aluminum shells cast to near net shape, then machined on the critical surfaces.
Machined or printed prototypes for fit checks before tooling is committed.
Anodizing, powder coating, plating and bead blasting after machining.
Small-batch urethane and low-volume castings for early build phases.
Numbers your process planner can check against the drawing.
| Item | Range |
|---|---|
| Achievable tolerance | ±0.005 mm (±0.0002 in) |
| Surface finish | Ra 0.2–3.2 μm by process |
| Standard finish | Ra 0.8–1.6 μm |
| Maximum part size | 4,000 mm |
| Large travel | 4,000 × 400 × 150 mm |
| Medium travel | 750 × 1,150 × 550 mm |
| Rotary table | Ø400 mm |
| Machines on site | 127 high-precision CNC |
| Inspection | 100% before shipment |
Fifteen years in Dongguan, three plants, one quality system.
Three wholly-owned plants across 7,600 m², with 150 technicians on the floor.
Not just a lab figure. Process capability is monitored through the run.
Out of 127 CNC machines, plus 16 mill-turn centers for shaft-side work.
Raw material check, in-process monitoring and final inspection on every lot.
Send a model, get a quotation with manufacturability notes the same day.
From one prototype to runs above 10,000 parts on the same program.
Motor and gearbox share one casting. Bore alignment decides noise.
IATF 16949 documentation required from first article onward.
Low volume, geometry still moving, no tooling budget yet.
Stiffness and mass trade off against each other at every revision.
Yes. Send the casting drawing and the machined drawing. We probe each blank, shift the toolpath to the real surface, and cut the bore, face and dowel pattern from the same datum.
If the casting shift is larger than the machining allowance, we flag it before the run instead of cutting through a wall.
±0.005 mm is achievable on bore diameter and position when the part is cut in one setup and the machine is thermally stable.
Tighter bores are usually handled by leaving stock and finishing after any heat treatment, so the final geometry is cut last.
At 300 pieces, billet is normally the lower total cost because die tooling is not amortized.
If the geometry is frozen and you expect 5,000 or more per year, a cast shell with machined bores usually wins on unit price.
We stress-relieve where the material allows, keep finishing cuts light, and control how the part is racked during coating.
For flanges with a flatness callout, we check flatness after finishing rather than only on the freshly machined part.
Dimensional data on the critical features, material certification for the lot, and inspection records on request.
We can also supply a full dimensional report against the drawing's tolerance block if your quality team needs it.
Quotation and DFM analysis come back within 12 hours. Production can start within 24 hours of a released order.
Standard parts ship in 3–5 days. Larger housings or coated parts add time for finishing, which we confirm before the order starts.
Yes. Uploads are handled as confidential and an NDA is available on request before you send files.
We do not share customer drawings, models or part photographs.
Raw material check on receipt, in-process monitoring during cutting, and final inspection on 100% of parts.
Reports are issued on request, and any non-conforming feature is caught before the pallet leaves the plant.
Upload your model. We come back with a quote, a DFM note and a suggested route within 12 hours.
12-hour quote100% inspectionNo minimum order quantityNDA on request
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Upload your 3D model or 2D drawing and get a quotation with a free DFM analysis. Maximum processing size 4,000 mm.
CNC Metals 13 grades
CNC Plastics 10 grades
Machines & processes 12 options
Surface & post-processing 10 options
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