China Online CNC Machining Services

Ordering from an overseas machine shop is mostly a file problem. Send a STEP or IGES model plus a 2D drawing that carries the GD&T callouts. The 3D model defines the shape; the drawing defines what actually matters. When a thread, a press fit or a sealing face exists only on the model, we cannot know whether it is critical or cosmetic, and the quote will carry an assumption you did not intend.

Native CAD files are also fine. SolidWorks, NX, Creo and Inventor all open here. Delays usually come from a drawing that disagrees with the model, for example a Ø12 mm hole in the model and Ø12.5 mm on the drawing. We stop and ask rather than pick one.

Once the files land, our engineers do a free DFM analysis and return a quotation within 12 hours. The DFM note lists the features that will be hard to hold, the places where a tighter tolerance buys nothing, and any setup that could be replaced by a standard tool. You approve the revision, and production can start within 24 hours.

Uploads stay confidential. A signed NDA is available on request before you send anything, and files are not shared outside the project team.

• 1
  SendSTEP, IGES or native CAD plus a drawing with GD&T
• 2
  Get backDFM notes and a quotation within 12 hours
• 3
  ApproveProduction can start within 24 hours of sign-off

A single prototype can be dialed in by hand. A 5,000-part run cannot. The number that matters is not what the shop can hit once, but what it holds across every setup, every tool change and every shift. Our general machining tolerance is ±0.005 mm (±0.0002 in), and we quote tighter callouts only after checking the feature geometry and the material.

Two features decide this more than anything else: wall thickness and depth-to-diameter ratio. A 0.5 mm aluminum wall on a 100 mm part will move after machining, no matter how good the machine is. A Ø3 mm hole drilled 30 mm deep needs a pilot, a peck cycle and probably a reamer. Both are doable. Both change the price.

Surface finish follows the same logic. As-machined parts sit at Ra 1.6–3.2 μm. A high-finish requirement of Ra 0.8–1.6 μm is normal for sealing faces and bearing bores. Fine finish at Ra 0.2–0.8 μm is a lapping or polishing operation, not a milling one, and it belongs on the drawing only where a gage or a seal touches the surface.

We inspect 100% of parts before shipment: incoming material check, in-process monitoring and final inspection, with dimensional reports on request.

• 1
  General tolerance±0.005 mm (±0.0002 in)
• 2
  As-machined finishRa 1.6–3.2 μm
• 3
  High-finish areasRa 0.8–1.6 μm
• 4
  Fine finishRa 0.2–0.8 μm, polished or lapped

An online order is only as good as the floor behind it. GreatLight runs 127 high-precision CNC machines across three wholly-owned plants, with 150 technicians and 7,600 m² of production area in Dongguan, plus a factory in Singapore at No.3 Joo Koon Circle. The Dongguan site sits in Chang'an District, next to Shenzhen.

For engineers, the useful split is by part size and by how many faces need work. A 16-machine bank of simultaneous 5-axis machining centers handles parts with angled features, undercuts or contoured surfaces that would otherwise need three or four fixtures. Twelve four-axis mills cover parts that are mostly prismatic but need work on a fourth face. The 27 three-axis machines take the flat, simple work at the lowest cost per part.

Sixteen mill-turn centers cover parts that combine turning and milling, so a shaft with cross-drilled holes and milled flats does not need two separate setups and two separate tolerance stacks. Maximum processing size is 4,000 mm. Travels run from 4,000 × 400 × 150 mm for long parts down to 500 × 310 × 200 mm for compact ones, with a Ø400 mm rotary table for round work.

Tooling, fixtures and programming are in-house, so a change to the model does not wait on an outside vendor.

• 1
  5-axis16 simultaneous centers
• 2
  4-axis and 3-axis12 mills, 27 machines
• 3
  Mill-turn16 centers, one setup for turned and milled features
• 4
  Max size4,000 mm

Online ordering works well for machined metal and plastic parts up to 4,000 mm, in runs from one prototype to 10,000+ pieces, with no minimum order quantity. It works badly for a few specific cases. Say so early and we will tell you the same thing rather than take the job.

Castings with internal cores that cannot be reached by a tool are a die casting or investment casting job, not a machining one. A part that needs a forged grain structure for fatigue life should be forged first and machined second. And a part with a hardness above roughly 45 HRC normally needs grinding, EDM or a pre-hardened stock strategy, which changes the process plan rather than the machine.

Very thin walls are the other common problem. Below about 0.8 mm in aluminum and 0.5 mm in stainless, chatter and distortion become the limit, not the tolerance. We will still quote it, but expect a fixture and a slower cycle, and expect the price to reflect that.

Where the geometry allows it, we suggest a small design change instead: a rib, a fillet or a slightly thicker wall. That usually costs less than holding a hard tolerance on a weak feature.

• 1
  Good fitPrismatic and turned parts, one-off to 10,000+
• 2
  Wrong fitComplex internal cores, forged grain structure
• 3
  Hardened partsAbove ~45 HRC, plan for grinding or EDM

Four certifications cover most of what buyers ask for. ISO 9001:2015 covers the quality system. IATF 16949:2016 covers automotive and EV work. ISO 13485:2016 covers medical devices. ISO 27001:2022 covers information security, which is the one that matters when you are sending unreleased designs to a supplier on another continent.

Inspection follows the drawing, not a sampling plan you have to negotiate. Incoming material is checked against the mill certificate, dimensions are monitored during the run, and every part is inspected before shipment. Dimensional reports, material certificates and first-article reports are available on request.

Confidentiality is handled the same way. Uploads are secure and confidential, an NDA is available before the first file transfer, and access to customer data is limited to the engineers on that project. If your program requires a specific NDA format, send yours and we will review it.

Historical late-delivery probability sits below 2%. That is not a promise about your specific order, but it does describe how the schedule usually behaves.

• 1
  ISO 9001:2015Quality management system
• 2
  IATF 16949:2016Automotive and EV
• 3
  ISO 13485:2016Medical devices
• 4
  ISO 27001:2022Information security

A quotation and DFM analysis come back within 12 hours. Production can start within 24 hours of approval, and parts ship in 3–5 days for standard work. Those numbers hold for parts that fit the machine bank and do not need a new fixture or an outside process.

Four things move the price. Material choice is the first, and titanium or 17-4PH stock costs several times what 6061 aluminum does. Feature count is the second, because every new tool and every new orientation adds setup time. Tolerance is the third, and tightening one callout from ±0.05 mm to ±0.005 mm can double the cycle on that feature. Finishing is the fourth: anodizing, electroless nickel, powder coating and laser marking are quoted as separate operations.

Laser marking has one practical limit. Minimum character height is 1.5 mm, so a full serial number on a small part needs either a shorter code or a different marking method. Tell us the data you need to mark and we will say whether it fits.

Runs scale without a step change. There is no minimum order quantity, so the same process that makes one prototype can make the first 10,000 parts.

• 1
  Quote + DFMWithin 12 hours
• 2
  Production startWithin 24 hours of approval
• 3
  Shipping3–5 days for standard parts
• 4
  MOQNone, from one part to 10,000+