Advanced CNC Machining Service

A standard 3-axis job is a straightforward transaction: one setup, one face at a time, simple geometry, loose-ish tolerance. An advanced CNC machining service takes on the parts that break that model. Multi-sided features that would need four or five re-fixturings. Thin walls that move when the clamp releases. Tight position tolerance between bores that sit on different axes. These parts cost more not because the machine is fancier, but because process planning carries most of the risk.

The dividing line is usually setup count, not part size. A 900 mm bracket with one flat face and six holes is ordinary work. A 60 mm aluminum housing with a bored bore, an angled port, and a sealing face all needing ±0.005 mm relative to each other is advanced work even though it fits in your hand. When a print calls for datum structures across three or more faces, that is the signal to stop quoting it as simple milling.

GreatLight has run this kind of work since 2011 from Dongguan, with 3 wholly-owned plants, 7,600 m² of floor space, and 150 technicians. The machine list matters less than the setup logic behind it, but the list is still the starting point: 127 high-precision CNC machines, of which 16 are simultaneous 5-axis machining centers, 12 are four-axis mills, 27 are three-axis machines, and 16 are mill-turn centers. A Singapore factory covers customers who need a second production location.

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  Setup count is the cost driverEach re-fixturing adds stack-up error and labor; 5-axis removes setups, not just cycle time.
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  Datum structure tells you the classFeatures referenced to three or more faces rarely belong on a 3-axis quote.
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  Thin walls need process, not just precisionRough, stress-relieve, semi-finish, finish. Skip a step and the part moves after unclamping.

Three-axis machining suits plate work, pockets, and parts where every feature is reachable from one direction. It is the cheapest option and often the right one. Four-axis adds a rotary axis, which lets you cut around a cylindrical or prismatic part in one setup. That covers a lot of shafts, manifolds, and connector bodies. Five-axis simultaneous machining is where contoured surfaces, undercut features, and compound angles become practical without a custom fixture.

Travel limits decide feasibility before anything else. The largest envelope here is 4,000 × 400 × 150 mm for long, slender parts such as rails and beams. Mid-size work runs on 750 × 1,150 × 550 mm and 600 × 600 × 600 mm machines. Compact precision parts use 500 × 500 × 450 mm and 500 × 310 × 200 mm platforms, and a Ø400 mm rotary table handles round and disc-shaped parts that need indexing.

Mill-turn centers are worth calling out separately. When a part has turned diameters and milled flats or cross-holes, splitting it between a lathe and a mill means two fixtures and two chances to lose concentricity. A mill-turn center holds that relationship in one setup, which is usually the difference between a part that assembles and one that needs rework.

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  Use 3-axis whenAll features are reachable from one or two directions and tolerance is looser than ±0.02 mm.
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  Use 4-axis whenThe part is rotational or prismatic and features repeat around an axis.
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  Use 5-axis whenContoured surfaces, compound angles, or deep undercuts would otherwise need custom fixturing.
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  Use mill-turn whenTurned and milled features must stay concentric to each other.

Aluminum is the default for prototypes and most brackets. 6061 and 6061-T6 machine cleanly and hold tight tolerance well. 7075 gives higher strength but is gummier and needs sharper tooling and more attention to chip evacuation. 2024 and 5052 behave differently again, and ADC12 shows up on die-cast parts that need secondary machining. If you are switching from 6061 to 7075 for strength, expect the cycle time and tool wear to move.

Stainless is where process planning earns its keep. 303 and 304 are common; 316 and 316L bring corrosion resistance but work-harden quickly, so light depths of cut and constant feed are required. 17-4PH (SUS630) machines well in the solution-treated condition and then gains hardness after aging, which is often better than trying to cut it hard. 440C is for wear surfaces and is unforgiving on small internal features.

Titanium and nickel alloys are the slow end of the range. TC4 (Ti-6Al-4V) and TA2 need low cutting speeds, high coolant pressure, and rigid setups. Inconel is worse. These materials are worth it when the application demands them, and rarely worth it when a coated steel or stainless would meet the spec. Copper and brass, including beryllium copper and C36000, machine fast but are soft and easy to mark, so handling and fixturing matter as much as the cut.

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  Aluminum6061, 6061-T6, 2024, 5052, 5083, 6063, 6082, 7075, ADC12.
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  Stainless303, 304, 316, 316L, 420, 430, 431, 440C, 17-4PH (SUS630).
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  Steel1018, 1045, 4130, 4140, 4340, A36, tool steel.
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  SpecialTA1, TA2, TC4 (Ti-6Al-4V), Inconel, magnesium AZ31B / AZ91D, PEEK, POM, PC, ABS, carbon fibre.

The tolerance figure is ±0.005 mm (±0.0002 in) on qualifying features. That number only means something when the print defines which features it applies to. A drawing with a blanket ±0.005 mm note across every dimension is harder to produce than one that reserves tight tolerance for the mating surfaces and lets everything else sit at ±0.05 mm. Narrowing the tight zone usually cuts cost without affecting function.

Surface finish follows a similar logic. As-machined surfaces land around Ra 1.6–3.2 μm, a good general finish around Ra 0.8–1.6 μm, and fine finishes reach Ra 0.2–0.8 μm. Getting below that generally means a secondary operation rather than more time on the machine. Specify finish only where a seal, bearing, or optical path needs it.

Inspection is 100% before shipment and covers raw material check, in-process monitoring, and final inspection. Reports are available on request. For medical and automotive programs the relevant systems are ISO 9001:2015, IATF 16949:2016, ISO 13485:2016, and ISO 27001:2022. Incoming drawings and models are handled under NDA on request, and uploads stay confidential. If your quality team needs a specific report format or a first-article layout, say so at quote time rather than after the parts ship.

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  Tight zone, not blanket toleranceReserve ±0.005 mm for mating features and relax the rest.
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  Finish where it functionsSealing faces and bearing bores need Ra 0.8 μm or better; cosmetic interiors do not.

Send a 3D model plus a 2D print with the critical dimensions and datum callouts. If the print is incomplete, note which features are functional and which are reference. That single clarification often removes a round of questions. A DFM analysis comes back within 12 hours of the quote request, and it will point out features that are hard to hold, thin walls that will move, or tolerances that cost more than they need to.

Production can start within 24 hours of approval, and parts typically ship in 3–5 days. There is no minimum order quantity, so a single prototype and a 10,000+ part run go through the same quoting process. If the design is not settled, rapid prototyping and vacuum casting are available before committing to hard tooling. Surface finishing, including anodizing, plating, powder coating, black oxide, bead blasting, brushing, polishing, and laser marking, runs in-house so the part arrives ready to install.

One caution on scheduling: a 5-axis part with a tight tolerance zone and a fine surface finish is not a 3–5 day part in every case. The lead time depends on whether the process needs stress relief, multiple semi-finish passes, or a first-article inspection before the run continues. Ask for the realistic date on those features rather than the standard one.

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  SendSTEP model, 2D print, critical dimensions, datum scheme, material, finish, and quantity.
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  Expect backQuote and DFM analysis within 12 hours. Production start within 24 hours of approval.
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  Ask aboutFirst-article inspection and any stress-relief step that affects the delivery date.