01
3 mm walls on a 200 mm housing
Thick sections cool slower than the ribs beside them. That difference pulls the part out of flat and leaves a shrink void in the middle of the boss. A 1.0–1.5 mm wall with ribs holds shape and cuts cycle time.
Die Casting Technology
Die Casting Technology for Aluminum and Magnesium Parts
We cast thin-wall housings and brackets in ADC12, A380 and AZ91D, then machine critical faces to ±0.005 mm in the same plant. Tooling, casting and finishing sit under one roof in Dongguan.
ADC12 / A380 / AZ91DWall 1.0 mm min±0.005 mm after machining3–5 day shippingNo MOQNDA on request
2011Casting and machining since
127High-precision CNC machines
±0.005 mmMachined tolerance
99.99%Qualification rate
Where castings go wrong
Four Problems That Show Up After the First Shot
Most failures trace back to design decisions, not machine faults. Here is what we see on incoming drawings.
02
No draft, then a stuck part
Zero draft on a 60 mm deep pocket needs high ejection force. The part drags, the corners scuff, and the die wears on every cycle. One degree of draft on that depth costs nothing and removes the problem.
03
Tolerance called on every surface
Blanks come out of the die with 0.1–0.3 mm variation on non-critical faces. Machining all of it triples cycle time. Better: mark three datum faces, machine those, and leave the rest as-cast.
04
Porosity found at final inspection
Gas trapped in a thick boss shows up only after anodizing, when the pit turns dark. Vacuum assist and a shorter fill time move the gas out before the shot freezes. We check with X-ray on request.
How we run it
From Cavity Layout to Finished, Inspected Parts
Tooling, casting and CNC machining in one plant removes the handoff where most delays start.
Casting
A 750 t Cell for Thin-Wall Aluminum
Aluminum loses heat fast, so the shot has to fill the cavity before the metal freezes. On our cold-chamber machines we set gate area and fill time together, then trim wall thickness to what the part actually needs. Housings from 1.0 mm wall thickness and up run stable once the gate is right.
We cast ADC12 and A380 for aluminum, AZ91D and AZ31B for magnesium. Magnesium parts come out lighter for the same stiffness, which matters for handheld and robot arm segments. Both run in the same plant as our machining cells.
- 1Wall thickness1.0 mm minimum on aluminum, 1.2 mm on magnesium
- 2Draft1° on walls, 2° on deep ribs and bosses
- 3MaterialsADC12, A380, AZ91D, AZ31B
Post-machining
Machining the Faces the Die Cannot Hold
A die holds 0.1–0.3 mm on non-critical surfaces. Bearing bores, seal grooves and mounting pads need better than that, so we machine them after casting on the same site. Four-axis and 5-axis centers cut datum faces, bores and threads in one setup where the geometry allows.
Tolerance on machined features is ±0.005 mm, with surface finish from Ra 0.2–0.8 μm on sealing faces to Ra 1.6–3.2 μm as-machined. Every part is inspected before shipment, and dimensional reports go out on request.
- 1Machined tolerance±0.005 mm on bores, pads and grooves
- 2Finish rangeRa 0.2–0.8 μm up to Ra 3.2 μm as-machined
- 3Machines16 simultaneous 5-axis centers, 16 mill-turn centers
Selection
Which Process Fits Your Part
Volume and geometry decide, not preference.
| Process | Best for | Volume band | Lead time |
|---|---|---|---|
| Die casting | Thin-wall housings, brackets, heat sinks | 1,000+ parts per year | Tooling, then 3–5 day cycles |
| Vacuum casting | Smooth cosmetic covers, bridge parts | 10–200 parts | Days, no steel tool |
| CNC from billet | Tight-tolerance plates, low count | 1–500 parts | 3–5 days |
| 3D printing | Form checks, jigs, fit trials | 1–50 parts | Days |
Services
Six Ways We Take a Part to Delivery
One plant covers the full chain, so nothing waits at a supplier boundary.
01
Metal Die Casting
Aluminum and magnesium castings in ADC12, A380 and AZ91D, with wall sections from 1.0 mm.
02
Vacuum Casting
Silicone-tooled urethane parts for cosmetic covers and fit checks before steel is cut.
03
5 Axis CNC Machining
Critical faces, bores and contoured pockets cut in one setup on 16 simultaneous 5-axis centers.
04
CNC Milling & Turning
Mill-turn work for threaded bosses, seal grooves and round features on cast blanks.
05
Rapid Prototyping
Machined and printed prototypes that let you test assembly before spending on tooling.
06
Part Surface Finishing
Anodizing, plating, powder coating, bead blasting and laser marking, all in-house.
Capability
What the Shop Can Hold
| Item | Range | Notes |
|---|---|---|
| Maximum part size | 4,000 mm | Largest travel 4,000 × 400 × 150 mm |
| Machined tolerance | ±0.005 mm | ±0.0002 in on critical features |
| Surface finish | Ra 0.2–0.8 μm | Fine finish on sealing faces |
| Materials | Aluminum, magnesium, zinc | ADC12, A380, AZ91D, AZ31B |
| Order quantity | No MOQ | One prototype to 10,000+ parts |
| Lead time | 3–5 days | Parts ship after 100% inspection |
Why GreatLight
Numbers Behind the Work
15Y
Casting and machining since 2011
Fifteen years of aluminum and magnesium work, most of it parts that have to fit something else.
127
High-precision CNC machines
Sixteen simultaneous 5-axis centers and sixteen mill-turn centers, so castings do not queue for machining.
±0.005 mm
Machined tolerance
Held on bores, pads and grooves after the die has done its part.
99.99%
Qualification rate
Every part inspected before shipment, with dimensional reports on request.
4
Quality frameworks
ISO 9001:2015, IATF 16949:2016, ISO 13485:2016 and ISO 27001:2022.
24 h
To production start
Quotation and DFM analysis within 12 hours, production can start within 24.
7,600 m²Manufacturing space
3Wholly-owned plants
150Technicians
<2%Historical late-delivery rate
What the parts must do
Where Castings Have to Hold Up
Automotive and EV housings
Motor housings, inverter covers and brackets that must stay flat after heat cycles.
- IATF 16949:2016
- ±0.005 mm bores
- 100% inspection
Robot arm and joint housings
Magnesium segments where mass matters and bores must align across a moving joint.
- AZ91D magnesium
- 5-axis in one setup
- 12-hour DFM
New energy and power parts
Heat-sink bodies and busbar housings with machined sealing faces and tight datum control.
- 4,000 mm max part
- Ra 0.8–1.6 μm
- 3–5 day shipping
FAQs
Questions Engineers Ask Before Tooling
What wall thickness can a die casting hold?
For aluminum, 1.0 mm is a practical floor on a well-gated part. Below that the metal freezes before it fills the far end of the cavity.
Magnesium runs a little thicker at 1.2 mm because the alloy flows differently. Where a wall needs to be thinner, we look at whether the section carries load or just closes a gap.
Why machine a casting instead of casting to final size?
A die holds roughly 0.1–0.3 mm on non-critical surfaces. That is fine for the outside of a housing and not fine for a bearing bore.
We machine only the features that need it, which keeps cycle time down compared with cutting every face to print.
When is vacuum casting a better choice than die casting?
Use vacuum casting for 10 to 200 parts, cosmetic covers, or a fit check before steel is cut. The silicone tool costs far less than a hardened die.
Once the annual volume passes roughly 1,000 parts and the geometry is stable, a die pays for itself and gives a better surface out of the mold.
How do you handle porosity in thick sections?
We shorten fill time and use vacuum assist so gas leaves the cavity before the metal freezes. Thick bosses are also the first place we suggest a change.
Where a part is safety-related or later anodized, we can check with X-ray and report what we find.
Can you cast and machine the same part in one order?
Yes. Tooling, casting and CNC machining run in the same plant, so a casting does not wait at a supplier boundary for its second operation.
That is also why we can quote a machined casting with both the cast tolerance and the machined tolerance stated separately.
What draft angle do you need on the drawing?
One degree on vertical walls is usually enough. Deep ribs and bosses want closer to 2° because the part has to release over a longer distance.
If your design is at zero draft, send it anyway. Adding draft early is cheaper than repairing die wear later.
Which materials do you cast?
Aluminum: ADC12, A380 and related alloys. Magnesium: AZ91D and AZ31B.
We also machine cast blanks in zinc and aluminum alloys such as 6061, 7075 and 2024 when the part is cut from billet instead.
How do you protect the design files we send?
Uploads are secure and confidential. We can sign an NDA before you send a drawing.
Our information security management system is certified to ISO 27001:2022.
Send a Drawing and Get a Casting Quote
Upload a STEP file for DFM analysis and a quote within 12 hours. No minimum order quantity, and parts ship after 100% inspection.
12-hour quote100% inspectionNo MOQNDA on request
