CNC Machining
Copper
Copper delivers supreme electrical and thermal conductivity combined with natural corrosion resistance. It is the uncompromising foundation for high-performance heat exchangers, electrical distribution components, and advanced RF microwave transmission systems.
Core Mechanical Properties
Purity and machinability dictate the choice of copper. Below is the typical mechanical data comparing standard ETP copper, high-purity Oxygen-Free copper, and high-machinability Tellurium copper (Half-Hard tempers).
| Alloy Grade | Yield Strength | Tensile Strength | Hardness (Rockwell B) |
|---|---|---|---|
| C110 (ETP Copper) | ~ 275 MPa | ~ 310 MPa | 35 - 45 HRB |
| C101 (OFE Copper) | ~ 260 MPa | ~ 300 MPa | 35 - 45 HRB |
| C145 (Tellurium Copper) | ~ 300 MPa | ~ 330 MPa | 40 - 50 HRB |
International Grade Comparison
Use our cross-reference chart to match American standards (ASTM/UNS) with European (DIN/EN) and Chinese (GB) copper material equivalents.
| ASTM / UNS (USA) | DIN / EN (Europe) | GB (China) | Key Characteristics |
|---|---|---|---|
| C11000 | CW004A / E-Cu57 | T2 | Electrolytic Tough Pitch (ETP). The most common commercial copper. Over 99.9% pure, offering massive electrical and thermal conductivity. |
| C10100 | CW009A / Cu-OFE | TU1 | Oxygen-Free Electronic (OFE) Copper. 99.99% pure. Crucial for vacuum tubes and high-end electronics where oxygen outgassing must be avoided. |
| C14500 | CW118C / CuTeP | QTe0.5 | Tellurium Copper. Contains ~0.5% Tellurium, boosting machinability to 85% (similar to brass) while maintaining excellent conductivity. |
Application Fit Matrix
Copper parts are usually specified for conductivity or heat transfer, so the plan should protect geometry and functional surface quality.
| Application | Recommended Material | Why This Material Works | Typical CNC Process | Finish / Risk Note |
|---|---|---|---|---|
| Busbars & Power Contacts | C110 Copper | Very high electrical conductivity for compact power distribution. | Milling, drilling, slotting | Specify edge breaks without reducing contact area. |
| Heat Spreaders & Thermal Plates | C110 or C101 Copper | Excellent heat transfer for electronics, lasers, and cooling interfaces. | Face milling, pocketing, drilling | Flatness and surface finish control thermal interface performance. |
| RF & Microwave Components | C101 Oxygen-Free Copper | High purity supports stable electrical performance and clean plating. | Precision milling, boring, tapping | Protect surfaces from scratches and oxidation before plating. |
| EDM Electrodes | C110 Copper | Conductive, machinable, and suitable for detailed electrode geometry. | High-speed milling, engraving | Sharp corners wear in use; match design to burn strategy. |
| Welding & Battery Fixtures | C110 Copper | Dissipates heat quickly and resists local overheating. | Milling, turning, drilling | Copper is gummy; allow realistic tolerances on deep narrow features. |
Selection Rule
Match the grade to the part's real job first: strength, heat, wear, corrosion, insulation, transparency, or cosmetic finish.
DFM Reminder
Material choice changes tolerance risk, burr control, wall thickness, thread strategy, and finishing route.
Quote Tip
Share the operating environment, mating parts, finish expectations, and inspection requirements with the drawing.
Expert Machining Tips
Pure copper (like C110) is incredibly soft and "gummy," making it notorious for clinging to cutting tools. Huade utilizes advanced techniques to maintain micro-precision:
- 1
Polished Flutes & Sharp Geometry
To prevent Built-Up Edge (BUE) where copper welds itself to the tool, we strictly use uncoated, highly polished solid carbide or PCD (Polycrystalline Diamond) tools with extremely sharp, positive rake angles.
- 2
Managing Thermal Expansion
Because copper absorbs and transfers heat so rapidly, the part itself can expand during aggressive machining. Copious amounts of coolant and strict temperature control are required to maintain tight dimensional tolerances.
- 3
Specifying Tellurium Copper (C145)
If your design requires complex Swiss turning, deep micro-hole drilling, or intricate internal threading, we highly recommend switching from C110 to C145. It machines almost like brass while retaining ~93% of pure copper's conductivity.
Top 3 Surface Treatments
Raw copper rapidly oxidizes and forms a green/brown tarnish when exposed to air and moisture. Proper surface finishing is essential for both performance and aesthetics.
1. Electroless Nickel Plating
The most popular industrial finish for copper. It prevents oxidation, increases surface hardness to prevent scratching, and maintains excellent electrical contact performance.
2. Silver / Gold Plating
Used in ultra-high-end RF and microwave components. Silver and Gold provide the absolute lowest contact resistance and highest resistance to environmental tarnishing.
3. Passivation / Anti-Tarnish Coating
If the raw, bright pinkish-orange aesthetic of copper is required (such as in high-end consumer products), an invisible anti-tarnish chemical dip or clear lacquer is applied to seal the metal from oxygen.
Start Your Manufacturing RFQ
Upload your 3D CAD files today. Our engineering team will review your copper specifications and provide a free DFM report along with rapid pricing.