01
A mating face that will not seat
A flatness callout held on the print but not on the part. The joint opens a gap at one corner, the gasket leaks, and you are reworking a batch instead of building the next one.
Metal CNC Machining
CNC Machining Metal: From One Prototype to 10,000+ Parts
We machine aluminum, stainless, steel, brass and titanium on 127 CNC machines in Dongguan. Send a STEP file and get a quote with DFM notes within 12 hours.
±0.005 mm toleranceNo minimum order quantity16 five-axis centersISO 9001 / IATF 16949NDA on request
127High-precision CNC machines
16Simultaneous 5-axis centers
4,000 mmMaximum processing size
99.99%Qualification rate
Where it goes wrong
Metal Parts That Look Fine on the Drawing and Fail in Assembly
02
Thin walls that chatter and bow
A 1 mm aluminum wall machined in three passes comes back wavy or bell-mouthed. The wall measures in tolerance at the end, but not in the middle where it matters.
03
The second batch does not match the first
Your prototype was fine. Then the tooling gets re-fixtured, the setups change, and hole positions drift. Two suppliers, two sets of numbers, and no clean way to tell which one is right.
04
A quote that arrives after the deadline
You send drawings on Monday and hear nothing for a week. The tooling slot closes, the launch slips, and the schedule absorbs a delay that had nothing to do with the design.
How we hold metal parts
One Shop for Metal Machining, From First Article to Volume
Machining strategy follows the part, not the other way around.
Setup strategy
Fewer Setups Means Tighter Position
Most position error on a metal part comes from moving it between operations. Every re-fixture adds a small stack-up that no tolerance on the print can describe. We plan the setup sequence before quoting: which faces can be cut in one orientation, which features need a second op, and where a five-axis machine removes a re-fixture entirely.
On the 16 simultaneous five-axis centers, compound angles, port faces, and undercut pockets come off in one cycle. That keeps datum relationships intact and shortens the path from print to finished part.
- 1One-cycle compound featuresAngled faces and intersecting holes cut without re-clamping.
- 2Datum carried through opsThe same reference face is used from first op to final inspection.
- 3Fixture designed for the partSoft jaws and dedicated plates for thin walls and irregular castings.
Material behavior
The Alloy Decides the Cut
6061-T6 cuts clean and holds a fine finish, which is why it covers most brackets, housings, and heat sinks. 7075 behaves differently under load and needs lighter radial engagement to avoid chatter on thin ribs. 304 stainless work-hardens at the cutter, so we keep the tool moving and avoid dwelling in the cut.
Castings and forgings bring their own problems: hard spots, porosity, and varying stock. We check incoming material and adjust speeds and depths per batch rather than running one program across every lot.
- 1Aluminum6061, 6061-T6, 2024, 5052, 5083, 6063, 6082, 7075, ADC12.
- 2Stainless and steel303, 304, 316L, 17-4PH, 1018, 1045, 4130, 4140, 4340, tool steel.
- 3Copper, titanium, specialC101, C110, beryllium copper, C36000, TC4 (Ti-6Al-4V), Inconel, AZ31B.
Selection guide
Which Machining Route Fits Your Metal Part
Match the process to geometry, quantity, and tolerance before you commit.
| Part situation | Recommended route | Why |
|---|---|---|
| Simple prismatic part, tight tolerance | 3-axis milling | Fastest cycle, easiest to inspect |
| Features on four sides | 4-axis or mill-turn | One setup, fewer datum shifts |
| Compound angles, deep pockets | 5-axis simultaneous | No re-fixture, better surface continuity |
| Turned shaft with milled flats | Mill-turn center | Turning and milling in one program |
| Thin wall under 1.5 mm | 5-axis with soft jaws | Controlled engagement, less deflection |
| Large frame up to 4,000 mm | Large-travel milling | Single setup across the full length |
What we run
Metal Machining Services Under One Roof
01
5 Axis CNC Machining
Simultaneous five-axis cutting for compound angles, port faces, and deep pockets. One setup holds the datum relationship through the whole part.
02
4 Axis CNC Machining
Rotary work for parts with features on four sides. The Ø400 mm rotary table covers housings, manifolds, and joint bodies.
03
3 Axis CNC Machining
27 machines for prismatic plates, brackets, and covers. Fast cycles and straightforward inspection for simple geometry.
04
CNC Milling & Turning
16 mill-turn centers handle shafts with milled flats, cross holes, and threads without moving the part between machines.
05
Rapid Prototyping
One-off metal prototypes cut from plate or bar. No minimum order quantity, so a single part is a valid order.
06
Surface Finishing
Anodizing, electroless nickel, plating, powder coating, black oxide, bead blasting, polishing, and laser marking.
Scope
Machine Range and What It Covers
Numbers we work to on a daily basis.
| Item | Range | Note |
|---|---|---|
| Tolerance | ±0.005 mm (±0.0002 in) | Held on critical features |
| Fine finish | Ra 0.2–0.8 μm | Ground or polished surfaces |
| Standard finish | Ra 0.8–1.6 μm | Most machined faces |
| As-machined | Ra 1.6–3.2 μm | Non-critical surfaces |
| Large travel | 4,000 × 400 × 150 mm | Long frames and rails |
| Medium travel | 750 × 1,150 × 550 mm | Housings and plates |
| Compact travel | 500 × 500 × 450 mm | Small precision parts |
| Rotary table | Ø400 mm | Four-axis and mill-turn work |
Why GreatLight
Capacity, Inspection, and Paperwork
15Y
Machining metal since 2011
Fifteen years on aluminum, stainless, steel, brass, and titanium parts. Three wholly-owned plants and 150 technicians across 7,600 m².
±0.005 mm
Tolerance we hold, not hope for
Critical features are measured against the print. Thin walls and bores get extra checks before the part leaves the machine.
12 h
Quote and DFM in half a day
Send a STEP file and drawing. You get pricing plus DFM notes on wall thickness, tool access, and tolerance stacking within 12 hours.
24 h
Production can start next day
Once the order is confirmed, material is pulled and the first setup begins. No queue behind larger contracts.
99.99%
Qualification rate
Raw material check, in-process monitoring, and final inspection on every run. Reports on request.
0
Minimum order quantity
From one prototype to 10,000+ part runs on the same program and the same fixture plan.
7,600 m²Manufacturing space
150Technicians
3Wholly-owned plants
<2%Historical late-delivery rate
What industries require
Metal Parts by Industry and What the Drawings Demand
Automotive & EV housings
Cooling channel alignment, flat sealing faces, and batch-to-batch repeatability across production runs.
- ±0.005 mm
- IATF 16949
- Batch repeatability
Electronics and control chassis
Thin aluminum walls, connector cutouts, and heat-sink faces that must stay flat after anodizing.
- 1 mm walls
- Ra 0.8–1.6 μm
- Anodizing
Robotics and automation
Joint bodies and arm segments with bores that must stay concentric through a single setup.
- Concentric bores
- 5-axis
- One setup
Industrial machinery spares
Small-lot replacement parts where the drawing is old and the datum has to be re-established from the part itself.
- Small lots
- No MOQ
- Reverse datum
FAQs
Questions Engineers Ask Before Sending Metal Parts
What file format do you need for a metal CNC quote?
Send a STEP or IGES file plus a 2D drawing with tolerances, material, and finish. If the drawing is missing, we mark assumed tolerances in the DFM notes so you can confirm them.
The quote comes back within 12 hours with pricing and DFM feedback. No minimum order quantity applies, so a single prototype is enough to start.
Which metals do you machine most often?
Aluminum covers most work: 6061, 6061-T6, 2024, 5052, 5083, 6063, 6082, 7075, and ADC12 castings. Stainless runs second, mostly 303, 304, 316L, and 17-4PH.
Steel grades include 1018, 1045, 4130, 4140, 4340, and tool steel. We also cut brass, copper, titanium TC4, Inconel, and magnesium alloys when the application needs them.
How tight can you hold a metal part?
±0.005 mm (±0.0002 in) is the working tolerance on critical features. That figure only holds when the feature is reachable in the setup we planned, so we flag anything that cannot be measured or cut that close.
Surface finish runs from Ra 0.2–0.8 μm on ground or polished faces to Ra 1.6–3.2 μm as-machined. Tell us which faces matter and we will leave the rest at the faster finish.
How do you keep the second batch matching the prototype?
The program, fixture, and inspection plan are frozen after first article approval. Same datums, same tool paths, same measuring points on every run.
If a fixture has to be rebuilt, we cut a first article again and compare it against the approved report before releasing the rest of the batch.
Can you machine thin walls and small features?
Yes, with limits. Aluminum walls down to about 1 mm are workable when the part is supported properly and the cut is planned to avoid deflection. Below that, the risk climbs fast.
For micro features, tell us the smallest tool you expect. Tool reach and chip evacuation set the real limit, not the machine spindle.
What inspection do you do before shipping?
Raw material check on arrival, in-process monitoring during cutting, and final inspection on every part. Nothing ships without passing the final check.
Inspection reports are available on request. We are certified to ISO 9001:2015, IATF 16949:2016, ISO 13485:2016, and ISO 27001:2022.
What is the lead time for metal parts?
Quotation and free DFM analysis come back within 12 hours. Production can start within 24 hours of order confirmation, and parts typically ship in 3–5 days.
That timeline assumes the drawing is complete and the material is standard stock. Special alloys and heavy fixturing add time, and we tell you before the order is placed.
How do you handle confidentiality?
Uploads are secure and confidential. We can sign an NDA before you send drawings, and we do not share customer files or part photos.
If your project needs it, ask for the NDA first and send the files after it is signed.
Send Your Metal Part and Get a Quote in 12 Hours
One prototype or ten thousand. Same program, same fixture plan, same inspection points.
12-hour quote100% inspectionNo minimum order quantityNDA on request
