Copper rod stock for EDM electrodes and high-conductivity parts
A copper electrode rod is a long bar of high-purity copper. Its main use is as EDM electrode stock: mold shops machine the rod on CNC mills or lathes into electrode shapes, clamp them in the EDM spindle and spark-erode the mold — for plastic injection molds, die-casting molds and IC connector molds. Copper rods are also used for plating racks and bus bars, ground rods, induction heating coils and laboratory electrochemical electrodes.
The size on this page, 8 mm × 600 mm, is a common EDM electrode stock size; it can be cut into 50–100 mm blanks and machined. A JIAHON affiliated company supplies customers throughout Taiwan. Purity ≥ 99.5% and 99.99% OFHC grade are available; COA and MTC documents on request.
Specifications
| Item | Details |
|---|---|
| Product | Copper electrode rod / pure copper rod |
| Size on this page | Purity > 99.5%, Ø8 mm × 600 mm |
| Purity grades | ≥ 99.5%; 99.99% OFHC (oxygen-free high-conductivity) optional |
| Common diameters | 4, 5, 6, 8 (this page), 10, 12, 15, 20, 25 mm (larger or custom on request) |
| Common lengths | 500, 600 (this page), 1000, 2000 mm; other diameters and lengths on request |
| Appearance | Reddish metallic luster, smooth surface (bright or drawn), good straightness |
| Density | Approx. 8.96 g/cm³ |
| Conductivity (IACS) | 99.99% OFHC grade ≥ 101% IACS |
| Hardness | HV 50–90 (soft / half-hard / hard) |
| Packing | 10–25 kg per bundle (PE film + cardboard) |
| Standards for reference | ASTM B187 / JIS H3140 / ISO 1640 |
Values other than the size on this page are common industry ranges; actual purity, size and surface depend on the application and the supplier’s specification sheet, confirmed case by case.
Applications
- EDM electrodes: plastic injection molds, die-casting molds and IC connector molds. The 8 mm rod is machined into electrode shapes (square, round, thin plate, irregular) and clamped in the EDM spindle. A common combination is graphite for roughing and copper for finishing.
- Plating racks and bus bars: work racks and power bus bars on PCB plating and surface treatment lines, machined into U-shaped racks or L-shaped bus bars. OFHC grade can be chosen for better corrosion resistance in plating baths.
- Ground rods: earthing electrodes for buildings, plants, telecom towers and substations; pure copper rods resist corrosion and conduct well. IEC 62561 covers earthing system components. Typical sizes are 8–12 mm × 1500–3000 mm; the 600 mm rod on this page suits short applications.
- Induction heating coils and electrochemical electrodes: copper wound into coils with water cooling for induction hardening, brazing and melting; pure copper electrodes for laboratory electrochemistry and electrophoresis.
How to choose
| Application | Purity | Diameter | Notes |
|---|---|---|---|
| General EDM mold electrodes | ≥ 99.5% | 6–12 mm | 8 mm suits small and medium electrodes |
| Precision EDM mold electrodes | 99.99% OFHC | 4–10 mm | Semiconductor packaging, IC lead molds |
| Plating racks and bus bars | ≥ 99.5% | 10–25 mm | High current |
| Ground rods | ≥ 99.5% | 8–12 mm | See IEC 62561 |
| Induction heating coils | ≥ 99.5% | 6–10 mm | Can be bent; water-cooled versions |
| Laboratory electrochemical electrodes | 99.99% OFHC | 3–8 mm | High purity avoids contaminating samples |
Copper vs graphite EDM electrodes
| Item | Copper electrode | Graphite electrode |
|---|---|---|
| Surface finish | High (Ra < 1 µm) | Medium (Ra 1–3 µm) |
| CNC machining speed | Slower (copper is soft and hard to cut fast) | Faster |
| Discharge stage | Finishing (small removal, fine finish) | Roughing (large removal, efficiency) |
| Electrode wear | Medium to high | Low |
| Typical use | Precision 3C molds, IC connectors, phone housings | Automotive molds, large parts |
In practice: rough out most of the material with graphite, then finish the final shape and surface with copper. Mold shops usually keep both and switch depending on mold size and precision.
EDM electrode workflow with 8 mm × 600 mm rod
- Electrode CAD design: discharge shape + spark gap 0.1–0.3 mm
- Cut blanks: 600 mm rod into 50–100 mm pieces
- CNC machining: mill or turn the electrode shape
- EDM: clamp in the EDM spindle and erode the mold
- Electrode rotation: replace at 30–50% wear with a spare electrode
Purchasing and storage tips
- For formal purchases to ASTM B187, ask for: composition analysis (Cu % and Fe / Pb / O impurities in ppm), mechanical properties (tensile strength, hardness HV 50–90), dimensional tolerances (diameter, length, straightness), surface condition, and certificate of origin.
- Copper is stable when dry but oxidizes on the surface in humidity. Light oxidation does not affect EDM machining, but heavy oxidation can affect the conductivity of plating racks and the long-term stability of ground rods. Store in the PE wrap in a dry place below 60% RH.
- Copper is soft; machine at low speed to avoid built-up edge.
When you request a quote, please tell us: purity, diameter, length, quantity and application.
Email us for a quote: [email protected]