Every kilogram of structural mass costs range. Die cast aluminum housings, trays and heat sinks replace welded steel assemblies, hold stiffness where the motor mounts, and pull heat out of power electronics. We cast, then machine to ±0.005 mm.
None of these show up on a datasheet. They show up in range tests and warranty claims.
Bearing bores come out 0.03 mm off true position. The rotor drags, the inverter fights it, and 4–6% of pack energy turns into heat instead of motion. On a 500 km car that is 20–30 km gone before the customer notices.
Welds add mass at every joint and create hard points that crack under vibration. A welded tray typically carries 15–25% more steel than a single cast part doing the same job. That mass rides on the chassis for the life of the vehicle.
Porosity under the mounting face raises thermal resistance. The IGBT module runs 15–20 °C hotter, the controller derates, and peak torque fades on a long climb. The casting looked fine on the incoming inspection bench.
Thin walls need ribs that add mass; thick walls trap gas. Either way the seal groove is machined after the distortion, so the gasket sits uneven and the enclosure fails the IP67 soak test on the line.
The role die castings play in an EV is set at the drawing stage, not on the bench.
A die cast motor housing consolidates the stator can, end bells, mounting bosses and cooling jacket into one part. Aluminum ADC12 or A356 gives a strength-to-weight ratio that a welded steel assembly cannot match at the same stiffness. Fewer joints means fewer places for vibration to start.
Stiffness matters more than raw strength here. The bearing bore has to stay round under 8 kN of rotor load, or the air gap closes and eddy losses climb. We check wall thickness against the filling simulation before the tool is cut, so ribs land where the bending moment is highest.
Power electronics lose efficiency as junction temperature rises. A die cast heat sink with a machined mounting face and cast fins spreads heat across the whole surface instead of a few contact points. The flatness of that face is what sets the interface resistance.
We machine the mounting face to Ra 0.8–1.6 μm and hold flatness across the footprint. Fins are drafted for release but kept thick enough to carry heat to the tips. If a design needs more surface area than the tool allows, we say so before the tool is cut rather than after.
Pick by wall thickness, volume and how much machining the interface needs.
| Part | Typical alloy | Wall range | Why this route |
|---|---|---|---|
| Motor housing | A356 / ADC12 | 4–8 mm | Stiffness and a machined bore |
| Battery tray | 6061 / ADC12 | 3–6 mm | Large footprint, low mass |
| Inverter housing | ADC12 | 2.5–5 mm | Thin walls, sealed groove |
| Heat sink | ADC12 / 6063 | 2–4 mm fins | Surface area and flat face |
| Transmission case | A356 / AZ91D | 5–10 mm | Load paths and bearing seats |
| Busbar bracket | 6101 / C110 | 2–4 mm | Conductivity plus stiffness |
One supplier for the cast blank and the finished interface.
Aluminum and magnesium castings for housings, trays and brackets. We review wall thickness and draft before tooling.
16 simultaneous 5-axis centers cut angled faces, seal grooves and bearing bores in one setup.
Mill-turn centers finish round features and flat faces without re-fixturing the casting.
Machined or printed prototypes to test fit and thermal path before the die is committed.
Anodizing, chromate conversion, powder coating and bead blasting for EV housings.
Low-volume urethane and silicone parts for brackets and covers during development.
| Item | What we do | What you get |
|---|---|---|
| DFM review | Wall, draft and gate check | Feedback within 12 hours |
| Tooling | Die design and first article | Sample parts for approval |
| Casting | Aluminum or magnesium | Near-net blanks |
| Machining | 5-axis, mill-turn, 3-axis | Finished to ±0.005 mm |
| Finishing | Anodize, plate, coat | Corrosion and wear protection |
| Inspection | 100% before shipment | Reports on request |
Three wholly-owned plants in Dongguan and Singapore. 7,600 m² of floor space and 150 technicians on the shop floor.
Held on bearing bores, seal grooves and mounting faces. Imperial equivalent ±0.0002 in.
16 simultaneous 5-axis centers, 12 four-axis mills, 27 three-axis machines and 16 mill-turn centers.
Long battery tray and frame sections run on the large-travel machines without splitting the part.
Send a model and we return a quotation plus free DFM analysis within 12 hours.
Production can start within 24 hours. Parts ship in 3–5 days after release.
Bearing bores stay round under rotor load so the air gap does not close and eddy losses stay low.
Large cast or hybrid trays with machined mounting pads. Flatness holds across the pack footprint.
Machined mounting faces and cast fins keep junction temperature down so the inverter does not derate.
Yes, at equal stiffness. Aluminum is roughly one third the density of steel, and a single cast part removes the overlap and weld metal at every joint. A welded tray often carries 15–25% more material than a casting doing the same job.
The saving depends on geometry. If a part is a flat plate with no load path, welding is competitive. Casting wins when the part has bosses, ribs and a machined interface.
A356 when you need higher strength and better fatigue behavior around bearing seats. ADC12 when the part is thinner-walled and the priority is fill and surface finish.
Both machine well. If the housing sees high cyclic load at the mounts, A356 is the safer default.
0.5–1.0 mm on faces that will be machined, and 1.5 mm on bearing bores. That is enough to clean up distortion without cutting into the dense skin.
Leaving 3 mm or more wastes material and can expose subsurface porosity. We flag this in the DFM review.
Yes. The casting and the finishing operations run under one roof, so the blank does not ship out and back. That removes one set of handling marks and one tolerance stack-up.
First article samples go to you for approval before the production run.
Below 2 mm the metal freezes before it fills long sections, and you get cold shuts. Between 2.5 and 5 mm is the comfortable band for most EV housings.
If a design needs a thinner wall for mass, we look at whether ribs or a different alloy can carry the load instead.
Gate and overflow placement decides where the last metal solidifies. We put the gate so the mounting face fills early and the biscuit takes the shrinkage.
After machining, the face is inspected for exposed porosity. If a void opens, the part is scrapped rather than patched.
There is none. We run from one prototype to 10,000+ part runs. Tooling cost is the fixed part; the per-part cost falls as volume rises.
For early development, a machined prototype often makes more sense than cutting a die.
Yes. Uploads are handled as confidential and an NDA is available on request before you send models.
We are certified to ISO 27001:2022 for information security, alongside ISO 9001:2015 and IATF 16949:2016.
Upload a STEP file and we return a quotation plus free DFM analysis. Production can start within 24 hours, and every part is inspected before it ships.
12-hour quote100% inspectionFrom one prototype to 10,000+
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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
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