Copper Parts Machining and Supply for Industrial Applications in Lufkin, TX

C101 oxygen-free electronic copper (OFE) contains 99.99 percent copper minimum with oxygen below 0.0005 percent. The ultra-low oxygen content eliminates the porosity and embrittlement risk during hydrogen-atmosphere brazing or annealing that affects C110 electrolytic-tough-pitch copper. C101 is specified for applications where the part will be hydrogen-atmosphere heat treated, brazed in a reducing atmosphere, or used in high-vacuum environments — conditions common in electronic assembly and precision instrument manufacturing. Its electrical conductivity is 101 percent IACS, essentially equal to the pure-copper standard. For the Lufkin market, C101 is used in high-frequency electrical contacts, precision grounding electrodes, and waveguide components for field communication equipment. C110 electrolytic tough pitch (ETP) copper at 99.9 percent purity and approximately 101 percent IACS conductivity is the standard commercial grade for bus bar, electrical conductor, and heat exchanger applications. Its slightly lower purity versus C101 makes it minimally less suitable for reducing-atmosphere processing but entirely acceptable for the vast majority of electrical and thermal conductivity applications. C110 plate, bar, and tube are stocked by electrical supply distributors serving the Lufkin market in standard sizes. Sheet from 0.010 to 0.125 inch thickness is used for bus bar fabrication; round bar from 0.25 to 4 inches diameter covers most machined fitting and contact applications. Tellurium copper (C14500) adds 0.4 to 0.7 percent tellurium to a high-purity copper base, which dramatically improves machinability (to approximately 90 percent of free-machining brass) while retaining 90 percent IACS conductivity. The tellurium forms copper telluride particles that act as chip breakers in machining, allowing CNC turning and milling of copper at feeds and speeds closer to those used for free-machining steel rather than the difficult low-feed regime required for pure copper. Tellurium copper is the grade of choice for precision connector bodies, relay contacts, electrical switch components, and instrumentation fittings where both conductivity and machining economy matter. Lufkin shops performing high-volume turning of electrical contacts or connector bodies typically stock C14500 bar in preference to C110 to reduce cycle times and tool wear.

Pure copper (C101 and C110) is notoriously difficult to machine to tight tolerances and good surface finish. Its extreme ductility causes chips to form long, continuous strands rather than breaking into manageable pieces — these stringy chips wrap around tooling, scratch finished surfaces, and create chip-packing hazards in blind bores. Pure copper also has a tendency to smear under cutting tools rather than shear cleanly, leaving a built-up edge on the tool face that degrades surface finish and dimensional accuracy. The result is that Ra 63 micro-inch surface finish on pure copper requires sharp tooling, correct geometry, and careful process management that adds cost versus equivalent work in brass or aluminum. Tellurium copper (C14500) solves most of these problems. The telluride inclusions act as internal chip breakers, producing short, manageable chips similar to free-machining steel. Surface finishes of Ra 32 to 63 micro-inch are routine, and tolerances of plus or minus 0.001 inch are held without special tooling. For precision electrical contact faces where Ra 16 micro-inch or better is required for low contact resistance, lapping with a diamond abrasive compound on a flat reference surface achieves the required finish on tellurium copper with less effort than equivalent finishing of pure copper. Brazing copper assemblies — common for heat exchanger tube-to-header joints and electrical bus bar connections — requires careful atmosphere control. Silver brazing alloys (AWS BAg-7, -28, or -34) in air require flux to prevent copper oxidation; hydrogen or dry nitrogen atmosphere furnace brazing eliminates flux residue and produces cleaner joints with full fillet geometry visible for quality inspection. Joint clearances for copper-to-copper brazing should be 0.001 to 0.003 inch for capillary brazing flow — wider than steel brazing joints because copper's thermal conductivity equalizes temperature across the joint quickly and reduces the driving force for capillary flow into tight gaps.