About 122|Phosphorus-deoxidized copper (99.9% copper, 0.02% phosphorus). The phosphorus removes dissolved oxygen, making this the standard copper for brazing and welding applications where
C110’s residual oxygen would cause embrittlement. Electrical conductivity drops to about 85% IACS due to the phosphorus — a meaningful penalty for electrical applications but irrelevant for plumbing, heat exchangers, and gaskets. Machines the same as C110 (badly). Used for plumbing tube, heat exchanger tubing, and any brazed copper assembly. Compare to C110 (better conductivity, can’t braze in reducing atmospheres) and
C101 (oxygen-free, highest conductivity).
