About 101|Oxygen-free electronic copper (99.99% pure, OFE grade). The highest-purity commercial copper. Zero oxygen content eliminates hydrogen embrittlement risk during brazing or welding in reducing atmospheres. Used for high-vacuum components, electron tubes, superconductor substrates, and ultra-high-purity applications. Electrical conductivity is 101% IACS. Machines the same as
C110 — gummy, soft, and requires the same tricks: sharp uncoated positive-rake tools, high speed, flood coolant. Costs significantly more than C110 due to the extra refining. If the application doesn’t specifically need oxygen-free copper, C110 saves real money. Compare to C110 (99.9% pure, adequate for most electrical applications) and C102 (same thing, different spec number).
