01
Thin walls move after clamping
A 1.2 mm wall on a 6061 housing looks fine on the machine and measures out of tolerance after unclamping. The fix is light finishing passes and a planned stress-relief step, not a slower spindle.
Aluminum CNC Milling
Machining Service Aluminum CNC Milling for Mechanical Parts
We mill aluminum mechanical parts to ±0.005 mm on 127 CNC machines, including 16 simultaneous 5-axis centers. Send a STEP file and get a quote with free DFM analysis within 12 hours.
6061 · 7075 · 6082Up to 4,000 mm partsRa 0.8–1.6 μm standardNo minimum order quantityISO 9001:2015IATF 16949:2016
127High-precision CNC machines
16Simultaneous 5-axis centers
±0.005 mmAchievable tolerance
150Technicians on staff
Common Problems
Where Aluminum Milling Projects Slip
These are the failures we hear about most from engineers moving a part from drawing to production.
02
Dimensional drift across a batch
Part one passes inspection and part 400 sits 0.03 mm off. Tool wear, coolant temperature and fixture repeatability all add up when nobody logs the offsets between runs.
03
Quotes that arrive after the deadline
A prototype quote that takes a week costs you the design review. Late DFM feedback is worse, because the change is already baked into the tooling.
04
Cosmetic marks on visible faces
Anodized parts show every tool mark and clamp dent. If the finish callout is only Ra 1.6 μm with no note on blend lines, the second operation will scratch the first face.
How We Machine It
A Process Built Around Aluminum
Aluminum cuts fast. The hard part is holding size and finish on thin sections and long parts.
Roughing and Finishing
Separate the Roughing Pass From the Finish Pass
Aluminum moves when you remove material. We rough with a stock allowance, let the part settle, then take the finishing cuts in a second setup or on a second machine. On 7075 brackets and 6061 enclosures this is the difference between a part that measures true on the bench and one that springs open after unclamping.
Climb milling with high-helix carbide tools keeps cutting forces low. For a 1.5 mm floor we reduce axial depth and raise spindle speed instead of pushing feed, which controls the built-up edge that ruins surface finish on soft alloys.
- 1Stress relief between operationsControlled for 6061-T6 and 7075 parts with thin ribs.
- 2Coolant temperature held steadyKeeps dimensions from walking during long runs.
- 3Tool wear logged per batchOffsets adjusted before parts drift out of tolerance.
Fixtures and Setup
Fixtures Decide the Tolerance, Not the Spindle
A 5-axis machine cannot save a part that is held badly. We design soft jaws, vacuum plates and dedicated fixtures around your geometry so the datum stays the datum through every operation. For a 4,000 mm rail or a Ø400 mm rotary-table housing, the fixture is quoted as part of the job, not added later.
Multi-sided parts run on our 16 simultaneous 5-axis centers, which means fewer setups and fewer chances to lose position. Where a part suits it, we use mill-turn centers to finish a turned bore and a milled face in one clamping.
- 1Dedicated soft jawsMachined to the part, not to a catalogue size.
- 2Fewer setups5-axis work on 16 centers cuts repositioning error.
- 3First-article sign-offDimensional report before the batch is released.
Alloy Selection
Which Aluminum Alloy Fits Your Part
A short guide to the grades we run most often for mechanical parts.
| Alloy | Typical use | Watch out for |
|---|---|---|
| 6061 / 6061-T6 | Enclosures, brackets, plates | Weld distortion near the joint |
| 7075 | High-load brackets, tooling | Lower corrosion resistance |
| 6082 | Structural frames, rails | Slightly harder to anodize evenly |
| 2024 | Aerospace fittings | Poor weldability |
| 5052 / 5083 | Panels, tanks, marine parts | Not for high-strength joints |
| ADC12 | Die-cast housings | Porosity if wall is under 1 mm |
Services
What We Run in the Shop
Aluminum milling is one route through the building. These are the others.
01
5 Axis CNC Machining
16 simultaneous centers for contoured faces, undercuts and multi-sided parts in one setup.
02
CNC Milling & Turning
Milled flats and turned bores finished on mill-turn centers to hold concentricity.
03
Rapid Prototyping
One-off aluminum parts for fit checks, with the same tolerance as production runs.
04
Sheet Metal Fabrication
Bent and punched aluminum enclosures, then machined where the tolerance is tight.
05
Part Surface Finishing
Anodizing, plating, powder coating, bead blasting and laser marking.
06
Custom 3D Printing
Plastic prototypes for form and fit before you commit to a machined aluminum part.
Capability Range
Machine Capacity and Tolerances
Numbers are shop limits, not targets. We quote against your drawing.
| Item | Range |
|---|---|
| Achievable tolerance | ±0.005 mm (±0.0002 in) |
| As-machined finish | Ra 1.6–3.2 μm |
| High-finish surfaces | Ra 0.8–1.6 μm |
| Fine finish | Ra 0.2–0.8 μm |
| Maximum part size | 4,000 mm |
| Large travel | 4,000 × 400 × 150 mm |
| Medium travel | 750 × 1,150 × 550 mm |
| Compact travel | 500 × 500 × 450 mm |
| Rotary table | Ø400 mm |
| Order quantity | 1 part to 10,000+ parts |
Why GreatLight
What a Machining Service Aluminum CNC Job Gets Here
Fifteen years of aluminum work, and the numbers behind it.
15Y
Machining since 2011
Three wholly-owned plants in Dongguan and a factory in Singapore, totaling 7,600 m².
±0.005
Tolerance held in production
Not just on a first article. Offsets and tool wear are logged through the run.
12H
Quote and free DFM
Drawing review comes back within 12 hours, and production can start within 24 hours.
99.99%
Qualification rate
Raw material check, in-process monitoring and final inspection on every order.
0
Minimum order quantity
One prototype or a 10,000-piece run on the same process and the same fixtures.
4
Quality systems in place
ISO 9001:2015, IATF 16949:2016, ISO 13485:2016 and ISO 27001:2022.
7,600 m²Manufacturing space
3–5 daysTypical part shipping
<2%Historical late-delivery rate
100%Inspection before shipment
Industry Requirements
What Each Sector Asks For, and What We Deliver
Automotive & EV
Machined housings and brackets on IATF 16949:2016 controlled lines.
- ±0.005 mm
- Batch traceability
- IATF 16949
Medical Devices
Cleanable aluminum components, deburred and passivated where the alloy allows.
- ISO 13485:2016
- Deburred edges
- Inspection reports
Electronics
Control chassis and heat-sink bodies with flat mating faces for gaskets.
- Ra 0.8–1.6 μm
- Flatness held
- Anodized finish
Industrial Machinery
Long rails and plates up to 4,000 mm, run as one-offs or low-volume batches.
- 4,000 mm max
- No MOQ
- 3–5 day shipping
FAQs
Questions Engineers Ask Before Ordering
What tolerance can you actually hold on aluminum?
±0.005 mm is our general limit for milling, and it depends on feature size and wall thickness. Thin walls under 1 mm and deep pockets are harder because the material deflects under cutting force.
Send the drawing and we will tell you which callouts we can hold as drawn and which ones need a design change. That answer comes back with the quote, within 12 hours.
Which aluminum grades do you keep in stock?
We machine 6061, 6061-T6, 2024, 5052, 5083, 6063, 6082, 7075 and ADC12. 6061-T6 covers most brackets, plates and enclosures. 7075 is for higher load or where stiffness matters more than corrosion resistance.
If your print names a temper or a mill certificate requirement, say so on the RFQ. Material certificates can be supplied on request.
Can you machine a part 4,000 mm long?
Yes. Our largest travel is 4,000 × 400 × 150 mm on the long-bed machines. Parts that long usually need support fixtures along the length to stop sag during cutting.
For anything over roughly 1,500 mm, send a model that shows the critical surfaces. We will quote the fixture along with the part.
How do you handle thin walls and warping?
We rough with stock left on, then finish in a later pass after the part has settled. Where the geometry is aggressive, we stress-relieve between operations.
Climb milling with reduced axial depth keeps the cutting force low. The trade-off is cycle time, which shows up in the quote.
What surface finishes are available on aluminum?
As-machined is Ra 1.6–3.2 μm. A high-finish pass gets Ra 0.8–1.6 μm, and fine finishing reaches Ra 0.2–0.8 μm.
For appearance, we offer anodizing in clear, color and hardcoat, plus bead blasting, brushing, polishing, powder coating and laser marking. Laser marking has a minimum character height of 1.5 mm.
Do you have a minimum order quantity?
No. We run one prototype or a 10,000+ part batch on the same machines and fixtures. Setup cost is spread differently, but the process does not change between quantities.
Low-volume runs of a few hundred parts are common for us, and we keep the fixture on file for repeat orders.
How is my design kept confidential?
Uploads are handled as confidential by default, and we can sign an NDA before you send files. Our quality systems include ISO 27001:2022 for information security.
If you need the NDA in place first, ask and we will send the document before the RFQ.
What do you need to quote an aluminum milling job?
A STEP or IGES file, the alloy and temper, the critical tolerances, the finish callout and the quantity. A 2D print helps most where you care about datum structure.
With those items we return a quote and a free DFM analysis within 12 hours. Production can start within 24 hours after you approve.
Send Your Aluminum Part for a Quote
Upload a STEP file and we will return a price with free DFM analysis within 12 hours. One part or ten thousand, no minimum order quantity.
12-hour quote100% inspection before shipmentNo minimum order quantityNDA on request
