In high-precision CNC machining, the diameter of your C10100 copper round bar is more than just a measurement; it dictates the tool-path strategy and the final seal integrity of your vacuum components. Sourcing 99.99% purity copper with a guaranteed 101% IACS conductivity is only the first step. For a machinist, the "gummy" nature of OFE copper means that even a minor deviation in diameter tolerance can lead to tool chatter or surface "smearing." As a leading supplier of C10100 Oxygen-Free Electronic copper, Henan Gnee New Material Co., Ltd. provides precision-drawn and extruded OFE copper bar stock that meets the most demanding ASTM B187 and B170 Grade 1 standards.
What are the standard diameters for C10100 copper round bars?
Availability is the primary driver of project lead times. We maintain a diverse stock of C10100 copper round bar diameters, ranging from ultra-fine pins to heavy-duty electrodes. While large-diameter bars are often provided as an extruded OFE copper bar, smaller diameters are typically cold-drawn to achieve tighter dimensional tolerances and a superior C10100 surface finish Ra.
If your design requires non-cylindrical formats, we also stock a full range of C10100 Round, Square & Flat Bar, including OFE copper flat bar and C10100 square rod configurations for high-current busbars.
C10100 Round Bar Weight and Diameter Reference
| Diameter (inch) | Diameter (mm) | Weight (lb/ft) | Weight ( kg/m ) | Common Application |
| 0.250" | 6.35 mm | 0.19 | 0.28 | Semiconductor Pins |
| 0.500" | 12.70 mm | 0.76 | 1.13 | High-Power Feedthroughs |
| 1.000" | 25.40 mm | 3.04 | 4.53 | CNC Machined Parts |
| 2.000" | 50.80 mm | 12.16 | 18.10 | UHV Flange Blanks |
| 4.000" | 101.60 mm | 48.66 | 72.41 | Heavy Induction Electrodes |
Why is the C10100 machinability rating only 20%?
The C10100 machinability rating is a common point of frustration on the shop floor. Because the material is 99.99% pure and lacks the lead or zinc found in brass, it doesn't "chip" cleanly. Instead, it "smears." As we analyzed in our C10100 vs. Brass, the superior conductivity of copper comes with a "gummy" mechanical tradeoff.
To maintain a precision finish on a C10100 square rod or round bar, you must use high-rake, polished carbide tools. A tight diameter tolerance ensures that the initial "roughing" pass remains consistent, preventing the tool from clogging and ruining the 101% IACS surface integrity.
How does OFE copper rod tensile strength affect your design?
The OFE copper rod tensile strength typically ranges from 30 ksi to 50 ksi, depending on the temper. For a design engineer, understanding the "yield" point is critical for ensuring that a C10100 copper round bar won't deform under its own weight or electromagnetic forces in a high-power transformer.
Before you specify a temper, consult our C10100 hardness and temper guide. A "Half-Hard" (H02) extruded OFE copper bar provides a higher yield strength than an annealed bar, which is vital for maintaining dimensional stability during high-vibration EV chassis operations.
Diameter Tolerances for Drawn C10100 Rod (ASTM B187)
| Diameter Range | Standard Tolerance | GNEE Precision Level |
| Up to 0.500" | +/- 0.002" | +/- 0.0005" |
| 0.501" – 1.000" | +/- 0.003" | +/- 0.0010" |
| 1.001" – 2.000" | +/- 0.005" | +/- 0.0020" |
FAQ
1. Can I use an OFE copper flat bar for high-frequency RF?
Yes, but the surface finish is critical. High-frequency signals travel on the "skin" of the bar. Any surface oxidation or roughness on the OFE copper flat bar will increase signal attenuation. We provide bright-finished bars to prevent this.
2. Is there a difference in purity between extruded and drawn bars?
No. Both start with 99.99% pure cathode. However, the drawing process provides a smoother finish and tighter diameter tolerances than an as-extruded OFE copper bar, which is better for automated Swiss-lathe machining.
3. How do you verify the Max 5ppm oxygen limit on bars?
Every batch undergoes an ONH (Oxygen, Nitrogen, Hydrogen) gas analysis. We provide the MTR (Mill Test Report) for every C10100 copper round bar to ensure it is "Hydrogen-Safe" for vacuum brazing.
4. Why did my C10100 square rod warp after machining?
This is usually caused by internal stresses from the cold-drawing process. For complex CNC Machining, we recommend a stress-relief anneal to ensure the bar remains straight during and after cutting.
5. Does the OFE copper rod tensile strength drop after welding?
Yes. As discussed in our C10100 welding guide, the heat-affected zone (HAZ) will naturally anneal and soften, potentially dropping the strength of the joint to the "Soft" (OS025) level.
6. Do you offer custom-ground diameters for electrodes?
Yes. If our standard OFE copper sheet standard sizes or round bar diameters don't fit your design, we provide centerless grinding to reach any custom diameter with tolerances as tight as +/- 0.0002".
Henan Gnee New Material Co., Ltd. Product Range
| Product Type | Shapes Available | Common Grades | Diameter/Thickness Range | Length/Width Range | Applications |
|---|---|---|---|---|---|
| Copper Tubes | Round, Square, Rectangular, Coiled | C10100, C10200, C11000, C12200, C12000 | OD: 0.5mm - 300mm Wall: 0.1mm - 20mm | Up to 6000mm or custom | HVAC, Plumbing, Heat Exchangers, Refrigeration, Hydraulic Lines |
| Copper Plates & Sheets | Flat Sheets, Perforated, Embossed, Tread Plate | C10100, C11000, C12200, C23000, C26000 | Thickness: 0.1mm - 200mm | Width: Up to 2500mm Length: Up to 6000mm | Electrical Busbars, Roofing, Cladding, Gaskets, Transformers |
| Copper Bars & Rods | Round Bar, Square Bar, Hexagonal Bar, Flat Bar | C10100, C11000, C14500, C17200, C18200 | Diameter: 1mm - 300mm | Length: 1000mm - 4000mm | Machined Components, Electrical Contacts, Busbars, Fasteners |
| Copper Wires | Round Wire, Flat Wire, Square Wire, Stranded, Braided | C11000, C11600, C17200, C17510 | Diameter: 0.05mm - 12mm | Coil weights: 1kg - 500kg | Electrical Wiring, Cables, Springs, Mesh, Welding Wire |
| Copper Strips & Coils | Thin Strip, Foil, Slit Coil, Profile Strip | C11000, C12200, C19400, C26000, C26800 | Thickness: 0.03mm - 5mm | Width: 2mm - 1000mm Coil ID: 300mm - 600mm | Transformers, Radiators, Shielding, Terminals, Connectors |
About Our Factory
We operate a full range of production lines including extrusion presses, cold drawing benches, high-speed rolling mills, slitting lines, and precision CNC machining centers, enabling us to produce copper tubes, plates, bars, wires, and strips entirely in-house. For quality assurance, we maintain a dedicated inspection laboratory equipped with spectral analyzers, universal testing machines, hardness testers, surface roughness testers, and optical measuring instruments. Every batch is tested for chemical composition, mechanical properties, and dimensional accuracy before shipment. Our production capacity reaches 500+ tons per month, and we hold ISO 9001:2015 certification with full traceability from raw material to finished product. Whether you need standard mill stock or custom-processed components, we deliver precision copper products with short lead times and complete material certification.
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