What Makes C10100 Oxygen-Free Electronic Copper Different
C10100 is the oxygen-free electronic grade of copper. Its copper content is at least 99.99% and oxygen is restricted to a maximum of 0.0005%, which is the feature that separates it from ordinary tough pitch copper. Because there are no oxide particles at the grain boundaries, the metal keeps its ductility through high-temperature brazing and welding, offers excellent electrical and thermal conductivity, and releases very little gas in vacuum service. Those characteristics make C10100 the reference material for vacuum electronics, high-frequency components, precision instruments and cryogenic equipment, and it is supplied as pancake coils, straight tube, plate, bar and custom profiles.
Typical Physical, Electrical and Thermal Properties
| Property | Typical value (annealed C10100) |
|---|---|
| Density | 8.94 g/cm3 |
| Melting point | about 1083 deg C |
| Electrical conductivity | about 101% IACS |
| Electrical resistivity | about 1.68 x 10-8 ohm-m |
| Thermal conductivity | about 391 W/m-K |
| Specific heat capacity | about 0.385 J/g-K |
| Coefficient of thermal expansion | about 16.8 micro-m/m-K |
| Modulus of elasticity | about 117 GPa |
Conductivity in this grade reaches or slightly exceeds the international annealed copper standard, and because the metal is free of oxide inclusions the conductivity is retained after brazing in a reducing atmosphere, where tough pitch copper can suffer hydrogen embrittlement.
Mechanical Properties and Temper Selection
| Property | Soft annealed | Hard |
|---|---|---|
| Tensile strength | about 210 MPa | about 275 MPa |
| Yield strength | about 50 MPa | about 245 MPa |
| Elongation | about 55% | about 10% |
| Hardness (Brinell) | about 45 HB | about 85 HB |
Pancake coils and layer-wound coils are normally supplied in the soft annealed condition, so that the tube can be straightened, bent and flared on site without cracking. Where mechanical support or dimensional stability matters more than formability, harder tempers are produced by controlled cold reduction. The required temper should be stated using the temper designations of the applicable standard, together with the tensile strength and elongation limits that will be verified on delivery.
Product Forms, Standards and Size Ranges
| Product form | Typical standard | Typical size range | Typical applications |
|---|---|---|---|
| Sheet, plate and strip | ASTM B152 | thickness 0.5-50 mm, width up to 1500 mm | electrical components, shielding, cladding |
| Seamless pipe | ASTM B42 | outside diameter 6-500 mm | industrial piping, heat exchangers |
| Tube for air conditioning and refrigeration | ASTM B188, ASTM B280 | outside diameter 6-100 mm, wall 0.4-3 mm | HVAC and refrigeration circuits, pancake coils |
| Bus bar, rod and bar | ASTM B187 | thickness or diameter 3-200 mm | conductive components, switchgear links |
| Wire and rod for electrical use | ASTM B49 | diameter from 0.02 mm upwards | windings, connectors, conductors |
Equivalent products in the Chinese system are designated under GB/T 5231, with copper tube ordered to GB/T 1527 for general purposes or GB/T 18033 for water and gas service. For water-carrying tube and fittings, standard tube grades are normally specified rather than oxygen-free electronic copper; C10100 is reserved for the applications where its purity, low oxygen content and conductivity are the deciding factors.
Coil Configurations, Applications and Quality Verification
Pancake coils are soft annealed tube wound flat into a compact package, which cuts transport volume; the tube is straightened and bent during installation, so it suits refrigeration, air conditioning and instrument lines.
Layer-wound coils deliver a straight, clean bore in long lengths for HVAC assembly lines and heat exchanger fabrication.
Electronics and vacuum devices use the grade for lead frames, connectors, waveguide components and vacuum tube parts.
Cryogenic busbars and magnet components exploit the conductivity and ductility that are retained at low temperature.
Because the useful properties of C10100 follow from its purity, verification is essential. Composition is confirmed by optical emission or combustion analysis, with oxygen determined by inert gas fusion; electrical conductivity is checked on finished tube by resistivity measurement; dimensions, wall thickness and concentricity are measured; and surface quality is controlled by eddy current testing or visual inspection. Hydrostatic or pneumatic testing is applied to tube intended for pressure service, and grain size or hardness is checked where a temper has to be demonstrated. Certificates of compliance with the ordered standard, listing the results of these tests, should accompany each shipment.
Frequently Asked Questions
Q: What does OFE mean in the C10100 designation?
OFE stands for oxygen-free electronic. It denotes copper with at least 99.99% Cu and a maximum oxygen content of 0.0005%, produced without oxygen-bearing residues so that the metal remains ductile after brazing or welding.
Q: Is C10100 suitable for refrigeration and air conditioning tube?
Yes. Soft annealed C10100 tube is supplied in pancake coils and layer-wound coils for refrigeration, air conditioning and instrument lines, where its formability and thermal conductivity are both useful. Tube for these duties is commonly ordered to ASTM B188 or ASTM B280.
Q: How does C10100 differ from C11000 and C10200?
C11000 is electrolytic tough pitch copper containing a small but deliberate oxygen content, which is acceptable for general wiring but can cause embrittlement on brazing. C10200 is oxygen-free copper without the electronic grade purity requirement, while C10100 combines oxygen-free melting with 99.99% minimum copper and about 101% IACS conductivity.
Q: Why are pancake coils supplied in the soft annealed temper?
Soft annealing gives about 55% elongation, so the coil can be straightened, bent and flared during installation without cracking. Harder tempers are available where higher strength or better dimensional stability is needed.
Q: What oxygen content is allowed in C10100?
The maximum permitted oxygen content is 0.0005%, which is about five parts per million, with copper at 99.99% minimum. This limit is what distinguishes the electronic grade from ordinary oxygen-free copper.
Q: How is C10100 verified before shipment?
By chemical analysis including oxygen determination, electrical conductivity measurement, dimensional and wall thickness checks, eddy current or visual surface inspection, and pressure testing for tube in pressure service, all reported on a certificate with the ordered standard.
