We machine C101 and C102 oxygen-free copper for busbars, RF cavities and thermal hardware. Tight tolerances, burr control and surface finishes that hold up after plating.
Four failure modes we see on incoming drawings and first-article reports.
Copper cuts soft and gummy. A toolpath written for steel pushes the material instead of shearing it, so bores close up after clamping is released and flatness drifts past ±0.05 mm. By the time the second op is done, the whole lot needs rework or scrap.
Pure copper smears rather than breaks. A burr on a busbar or connector face survives deburring, then flakes off inside the assembly. Loose copper particles are conductive, so a single one can short a board or block a vacuum seal.
Copper oxidizes fast. Parts machined with the wrong coolant or handled bare-handed arrive with fingerprints etched into the face. If the drawing calls for plating or a solderable finish, that oxide layer is the reason the joint fails.
A 1 mm copper fin on a heat sink or waveguide has almost no stiffness. Aggressive roughing stores stress in the material, and the finishing pass releases it. The part measures fine on the machine and wrong on the CMM an hour later.
Two things drive the result: how the tool enters the material, and how the part is held.
Copper does not need brute force. It needs a tool that shears cleanly. We run polished carbide with high rake angles and generous relief, kept sharp enough that the edge cuts instead of burnishing the surface. Dull tools are the fastest way to smear a copper face.
Speeds stay high and feeds stay firm. A light, fast pass with a sharp cutter leaves a better finish on C101 than a heavy slow one, because the material does not have time to work-harden at the cut. We control coolant chemistry separately from steel jobs so the surface does not stain before inspection.
Soft material moves under clamping pressure. We fixture thin copper on vacuum plates or with soft jaws machined to the actual part profile, so the load spreads instead of pinching one edge. Roughing and finishing happen in separate setups with a rest between them.
When a wall is under 2 mm, we take material off both sides in alternating passes rather than cutting one face to depth. The part stays balanced and the finished dimensions hold. Every copper job is measured after it comes off the machine and again after it reaches room temperature.
Match the grade to the electrical and thermal requirement first, then to the finish.
| Grade | Typical use | What to watch |
|---|---|---|
| C101 (OFE) | RF cavities, vacuum seals, high-end busbars | 99.99% purity; hydrogen embrittlement risk in brazing |
| C102 (OF) | Heat sinks, PCB contacts, general electrical parts | 99.97% purity; slightly wider grain structure |
| C110 (ETP) | Connectors, terminals, cost-driven electrical parts | Contains oxygen; not for vacuum or reducing atmospheres |
| Beryllium copper | Spring contacts, high-strength electrodes | Requires dust control and post-machining heat treat |
| C36000 brass | Fittings, valve bodies, threaded parts | Excellent chip breaking; not for high-current paths |
One shop for the machining, the finish and the inspection report.
16 simultaneous 5-axis centers handle contoured copper faces, angled ports and compound features in one setup. Fewer setups means less re-clamping on soft material.
Mill-turn centers produce bushings, electrodes and threaded copper fittings from bar. Live tooling cuts cross holes and flats without a second operation.
27 three-axis and 12 four-axis machines cover plates, housings and heat-sink bodies where the geometry is mostly prismatic.
Single copper prototypes for thermal and electrical testing, machined from plate or bar with the same tolerances as production.
Bead blasting, tumbling, brushing and polishing, plus electroless nickel, silver and gold plating for solderable or low-contact-resistance faces.
100% inspection before shipment with raw material check, in-process monitoring and final CMM reports on request.
The numbers we hold on copper work.
| Item | Range | Notes |
|---|---|---|
| Maximum part size | 4,000 mm | Up to 4,000 × 400 × 150 mm travel |
| Tolerance | ±0.005 mm | ±0.0002 in on critical copper features |
| Surface finish | Ra 0.2–0.8 μm | Fine finish for sealing and plated faces |
| Rotary work | Ø400 mm | Indexed and simultaneous table options |
| Volume | 1 to 10,000+ | No minimum order quantity on copper parts |
| Certifications | ISO 9001, IATF 16949, ISO 13485, ISO 27001 | Audited and maintained across all plants |
Data from the shop floor, not adjectives.
15 years of production experience across three wholly-owned plants in Dongguan and Singapore, 7,600 m² of manufacturing space.
±0.005 mm (0.0002 in) on critical features, verified on the CMM and reported before the parts ship.
Quotation and free DFM analysis within 12 hours. Production can start within 24 hours of approval.
Historical late-delivery probability below 2%. Parts typically ship in 3–5 days.
Every copper part checked before shipment: incoming material, in-process monitoring and final inspection.
Uploads are secure and confidential. A non-disclosure agreement is available on request before drawings are shared.
Busbars and RF components where conductivity and a clean solderable face matter.
High-current copper connections and thermal plates for battery and power systems.
Small copper electrodes and shielding parts with documented process control.
Waveguides, electrodes and wear parts where thin walls must stay flat.
C101 is 99.99% pure with oxygen below 0.0005%. C102 is 99.97% pure with oxygen up to 0.003%. Both are oxygen-free grades, but C101 is the tighter specification.
Pick C101 when the part sees vacuum, high-frequency RF or a reducing atmosphere during brazing. C102 covers most heat sinks, PCB contacts and general electrical parts at a lower material cost.
Pure copper is soft and ductile. Instead of forming a clean chip, the material tends to deform ahead of the cutting edge and weld to the tool, which pushes a burr onto the exit face.
The fix is a sharp polished cutter with a high rake angle, firm feed and no dwell in the cut. Coolant chemistry matters too, because a reactive fluid leaves the surface stained.
Yes, with the right setup. Thin walls need light clamping, alternating passes and a rest between roughing and finishing so stored stress releases before the final cut.
We verify dimensions after the part reaches room temperature. For walls under 1 mm, we discuss the geometry with you during DFM and flag anything that will not hold repeatably.
The grade, the volume of material removed and the finish specification drive most of the cost. C101 costs more than C110, and a Ra 0.2–0.8 μm face adds a finishing pass.
Because we carry no minimum order quantity, a single prototype is priced on the same basis as a 10,000-part run. The quote shows setup, material and machining separately.
Yes. Beryllium copper is machined with dust control and documented handling procedures because the dust is a health hazard. Chips and coolant are managed separately from other jobs.
If the drawing calls for a spring temper, we machine in the annealed state and note the required post-machining heat treatment on the traveler so it is not skipped.
Bare copper oxidizes within days. For solderable faces we recommend electroless nickel, silver or gold plating, applied after machining and a light surface prep.
If you need bare copper, we bag and seal parts immediately after a final clean so the oxide layer stays thin. Tell us the assembly process and we will match the finish to it.
We hold ±0.005 mm on critical features and machine up to 4,000 mm in length, with travel of 4,000 × 400 × 150 mm on the largest machines.
Surface finish ranges from Ra 1.6–3.2 μm as-machined down to Ra 0.2–0.8 μm for sealing and plated faces. The Ø400 mm rotary table covers indexed and simultaneous work.
Uploads are secure and confidential, and we can sign a non-disclosure agreement before you share files. Our quality system is certified to ISO 27001:2022 for information security.
We do not reuse customer geometry, toolpaths or fixtures on other jobs. If you need it, we can restrict a program to a named machine and operator.
Upload a STEP file and we will return a quotation with free DFM analysis within 12 hours. No minimum order quantity, from one prototype to 10,000+ parts.
12-hour quote100% inspectionNo MOQNDA on request
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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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