We machine 4140 alloy steel and other medical-grade alloys into fixtures, housings and drive components. Tolerances hold at ±0.005 mm, and every part gets inspected before it leaves the floor.
The first article measures fine. By part 300 the bore has crept 0.02 mm and the mating pin no longer seats by hand. We control thermal growth and re-check the datum on every batch, so the 500th part measures like the first.
A 4140 steel component that was not stress relieved or passivated drags residual magnetism into the assembly. The engineer finds it during system testing, not at incoming inspection. We confirm heat treat and demagnetization before packing.
Notes like Ra 0.4 μm on a seal face, no burrs allowed in a fluid path, and a 0.01 mm true position callout get missed. The parts arrive looking good and fail the functional test. Our DFM review flags those notes before the first chip is cut.
Material certs, heat lot numbers, inspection reports. When these arrive late or incomplete, the quality team cannot release the batch and the build slips a week. We keep the documentation pack with the job and send it with the parts.
One process from raw bar to inspected, documented parts.
4140 is a chromium-molybdenum through-hardening steel. At 28–32 HRC it machines cleanly, holds a thread, and takes a wear surface that plain carbon steel cannot. It is the usual pick for surgical instrument bodies, bone plate prototypes, and drive shafts inside a device.
The catch is heat treat. A part roughed at full hardness will move when the stress releases. We rough, stress relieve, then finish to size so the final dimensions sit where the print says. On a 200 mm shaft that sequence is the difference between a running fit and a scrapped lot.
A one-off part that measures in tolerance proves the machine can do it once. A run of 2,000 that stays in tolerance proves the process is controlled. Those are different problems, and the second one is where most medical hardware projects fail.
We run 16 simultaneous 5-axis centers, 16 mill-turn centers, and a Ø400 mm rotary table, all under one roof in Dongguan. Parts that need a milled face and a turned bore come off one setup instead of two, which removes a re-fixturing error that shows up at the 0.01 mm level. In-process probes check the critical features while the part is still on the machine.
A short guide to the trade-offs we see most often.
| Material | Typical medical use | Watch out for |
|---|---|---|
| 4140 steel | Instrument bodies, drive shafts, fixtures | Must be stress relieved before finish cuts |
| 17-4PH stainless | Surgical instruments, valve stems | Hard to hold a fine finish after aging |
| 316L stainless | Fluid path parts, housings | Gummy chips; light cuts, sharp tooling |
| Ti-6Al-4V | Implant-adjacent hardware, bone screws | Heat builds fast; coolant and feed matter |
| 6061-T6 aluminum | Imaging housings, brackets | Too soft for wear surfaces or threads |
| PEEK | Insulators, low-friction bushings | Machines clean; costly in large bar sizes |
Simultaneous 5-axis work for contoured housings and features that cannot be reached in three setups. Sixteen centers available.
Mill-turn centers for parts that combine a turned bore with a milled face, held concentric in one setup.
Fit and function samples before tooling is committed. Same inspection routine as production parts.
Anodizing, passivation, bead blasting, polishing. Finish called out on the print, measured after.
Enclosures, brackets and chassis that sit around the machined assembly, not just the machined part.
Machined parts, hardware and sub-components packed as one kit so the line does not sort bins.
What a job includes by default.
| Item | Range or detail |
|---|---|
| Tolerance | ±0.005 mm (±0.0002 in) on critical features |
| Surface finish | Ra 0.2–0.8 μm fine, Ra 0.8–1.6 μm standard |
| Maximum part size | Up to 4,000 mm, travel 4,000 × 400 × 150 mm |
| Materials | 4140, 17-4PH, 316L, Ti-6Al-4V, aluminum, PEEK |
| Order size | No minimum — one prototype to 10,000+ parts |
| Quality system | ISO 9001:2015, IATF 16949:2016, ISO 13485:2016 |
| Documentation | Material certs, inspection reports, heat lot records |
| Confidentiality | Secure uploads; NDA available on request |
Fifteen years of production work, three wholly-owned plants, and 150 technicians across 7,600 m².
Repeatable on production runs, not just on a first article. Measured with in-process probing.
Plus 12 four-axis mills, 27 three-axis machines and 16 mill-turn centers. 127 machines total.
Quotation and a free DFM analysis within 12 hours of receiving a usable print and 3D file.
Production can start within 24 hours, and parts ship in 3–5 days on standard jobs.
Parts that pass inspection on the first pass, across all programs.
4140 at 28–32 HRC, threaded and finished without burrs in the grip area.
Turned and milled in one mill-turn setup to keep the bearing journals concentric.
6061-T6 bodies with non-magnetic hardware and a clean anodized finish.
316L fittings with polished bores and no burrs left inside the flow path.
Yes. We machine to the hardness called out on the print, and we record the heat lot number with the job.
Send the range and we will tell you whether to rough before or after heat treat. Most 28–32 HRC work benefits from a rough, stress relief, then finish sequence.
±0.005 mm on critical features, measured with in-process probing and a final inspection before shipment.
If a feature needs tighter than that, say so at quoting. We would rather flag it up front than discover it after the first article.
Yes. Anodizing, passivation, plating, powder coating, bead blasting and polishing are coordinated with the machining job.
Finish is specified on the print and measured after processing, so the final part matches the drawing, not just the pre-finish part.
Uploads are secure, and we can sign an NDA before any file changes hands.
Files are used only for your job. We do not share drawings or part photos with other customers.
There is none. We run a single prototype or a 10,000+ part program on the same process.
Prototype parts go through the same inspection routine as production, so the first article is a real data point.
Quotation and a free DFM analysis come back within 12 hours. Production can start within 24 hours, and standard jobs ship in 3–5 days.
If a feature needs a finish or heat treat step, that adds time. We tell you the realistic date at quoting, not after.
Material certificates, heat lot records and inspection reports on request. Raw material is checked on arrival, monitored during machining, and inspected 100% before shipment.
If your quality team needs a specific report format, send the template and we will fill it in.
A 3D file (STEP or IGES), a 2D print with tolerances and finish callouts, material, quantity, and any heat treat or certification requirement.
If a dimension is missing or ambiguous, we ask before quoting rather than guessing at the price.
Quotation with a free DFM analysis within 12 hours. No minimum order quantity, 100% inspection before shipment, and an NDA on request.
12-hour quote100% inspectionNo minimum orderNDA available
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Upload your 3D model or 2D drawing and get a quotation with a free DFM analysis. Maximum processing size 4,000 mm.
CNC Metals 13 grades
CNC Plastics 10 grades
Machines & processes 12 options
Surface & post-processing 10 options
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