CNC Machining Companies Services: What to Compare

Most supplier lists rank companies by size or reputation. That tells you almost nothing about whether a specific shop can hold your tolerance on your geometry. Five numbers do most of the work.

Tolerance comes first. A shop quoting ±0.05 mm is not competing with one quoting ±0.005 mm; they are different businesses. Check what the shop can hold across a production run, not what a single sample reached once. Position tolerance, flatness and surface finish usually decide the machine, not the material.

Then machine mix. Five-axis capability matters when your part has features on four or more faces, deep cavities, or undercuts that would otherwise need multiple fixtures. GreatLight runs 16 simultaneous 5-axis machining centers, 12 four-axis mills, 27 three-axis machines and 16 mill-turn centers. That spread lets us route a part to the machine that holds it cheaply instead of forcing every job onto one platform.

Maximum part size sets the ceiling. The largest travel here is 4,000 × 400 × 150 mm, with medium platforms at 750 × 1,150 × 550 mm and 600 × 600 × 600 mm, and compact platforms at 500 × 500 × 450 mm and 500 × 310 × 200 mm. A Ø400 mm rotary table covers most round and cylindrical work. If your part is bigger than the envelope, no amount of skill fixes it.

Material range and finish range matter for cost. Aluminum 6061, 7075 and 2024 machine fast and cheap; 17-4PH stainless, Inconel and TC4 titanium cut slowly and wear tooling. Surface finish is priced the same way: Ra 1.6–3.2 μm as machined, Ra 0.8–1.6 μm for most mating surfaces, Ra 0.2–0.8 μm only where the function demands it.

Finally, the quality system. ISO 9001:2015 covers general process control. IATF 16949:2016 is what automotive and EV programs expect. ISO 13485:2016 applies to medical devices. ISO 27001:2022 covers information security, which matters when you send CAD files to an outside shop.

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  ToleranceAsk for the production tolerance, not the best-ever sample.
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  Machine mixFive-axis removes fixtures; mill-turn removes second operations.
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  EnvelopeConfirm maximum travel before quoting a large part.
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  CertificationMatch the certificate to your industry, not to a logo wall.

A price without a process plan is a guess. Send the 3D model, the 2D drawing with tolerances and datums, the material spec, the surface finish callouts, and the quantity you expect over the next year. Quantity changes the answer more than anything else on the list.

We quote and return a free DFM analysis within 12 hours. That analysis flags thin walls, tool access problems, tolerances tighter than the function needs, and features that would be cheaper as a separate operation. Production can start within 24 hours after you approve, and parts ship in 3–5 days for standard work.

There is no minimum order quantity. One prototype and a 10,000+ part run go through the same review. That matters when a design is still moving and you need three revisions before committing to tooling or a long production schedule.

Uploads stay confidential, and an NDA is available on request. If your program requires one, sign it before the first file transfer rather than after.

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  SendSTEP model, 2D drawing, material, finish, annual quantity.
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  Get backQuote plus DFM notes within 12 hours.
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  ThenApprove, start within 24 hours, ship in 3–5 days.

Bigger is not automatically better. A very large shop optimizes for volume, so a five-part prototype can sit in a queue behind a 50,000-part order. If your program is early-stage, a mid-size shop with dedicated prototype cells usually moves faster.

Watch for capability that only exists on paper. A supplier may list five-axis machining while subcontracting the actual cutting. That adds a handoff, and every handoff adds tolerance stack-up and schedule risk. Ask where the part is cut and who inspects it.

Communication style is a real criterion. If your questions come back as sales answers instead of engineering answers, you will spend the project re-explaining the drawing. A short call with the process engineer before you place the order saves weeks later.

Cost is the last filter, not the first. Two quotes that differ by 30 percent usually differ in process, not in margin. Compare the operation list, the fixture plan, and the inspection plan before you compare the number at the bottom.

GreatLight Metal Technology Co., Ltd. was founded in 2011 and now runs 3 wholly-owned plants covering 7,600 m², with 150 technicians and 127 high-precision CNC machines. The main plant is in Dongguan, China, with a second factory at No.3 Joo Koon Circle, Singapore 629032.

Tolerance capability is ±0.005 mm (±0.0002 in), with a 99.99% qualification rate and 100% inspection before shipment. Inspection covers raw material check, in-process monitoring and final inspection, with reports on request.

Services cover 5-axis, 4-axis and 3-axis machining, CNC milling and turning, rapid prototyping, sheet metal fabrication, 3D printing, die casting, vacuum casting and surface finishing. Finishes include anodizing, electroless nickel, zinc, silver and gold plating, powder coating, black oxide, bead blasting, tumbling, brushing, polishing, and laser marking down to 1.5 mm character height.

We work across aerospace, automotive and EV, medical devices, robotics and automation, electronics, industrial machinery and new energy. Different industries carry different paperwork, so tell us which one you are in at the start.

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  Scale3 plants, 7,600 m², 150 technicians.
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  Machines127 CNC machines, 16 of them simultaneous 5-axis.
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  Quality±0.005 mm, 100% inspection, reports on request.