Pure copper. Tellurium copper. Beryllium copper.

Pure copper (C101, C110) is very ductile and gummy — chips don't break, they form long stringy shavings that wrap around the tool. Surface finish is poor without specialized techniques. Solutions: use tellurium-alloyed C145 (80% improvement in machinability), very sharp carbide tools with polished flutes, high feed rates to minimize contact time, copious coolant. Our experience with copper machining means acceptable results even in pure copper.

OFE C101 (oxygen-free electronic): used when oxygen content matters — UHV vacuum, cryogenic superconducting applications, electron beam welding, hydrogen atmospheres. About 2× cost of C110. C110 ETP: 99.9% pure, contains ~0.04% oxygen. Adequate for 95% of electrical and thermal applications. Use C110 by default; upgrade to C101 only when application genuinely requires oxygen-free purity.

Beryllium compounds are toxic when inhaled — beryllium dust from machining must be contained. Our BeCu machining uses: dedicated machining area with HEPA dust collection, wet coolant to prevent airborne particles, proper PPE for operators, containerized chip handling. Finished BeCu parts are safe to handle — the hazard is only during machining. We machine BeCu routinely with proper safety protocols.

Yes — TIG welding with copper filler, argon shielding, preheated for thicker sections. Copper has high thermal conductivity so heat management during welding is important. For busbar and electrical connection welding, often soldered or brazed instead of welded. Ultrasonic welding for thin copper busbars is becoming standard in EV battery packs.

As-machined: bright copper surface, oxidizes to dark brown in air within days — must be coated or plated for long-term appearance. Common finishes: electroless nickel (passivation + paint primer), tin plating (for solderability), silver plating (for electrical conductivity), gold plating (for corrosion + conductivity in connectors), chemical passivation (slows oxidation without plating). For cosmetic applications, lacquer coating preserves bright copper appearance.

C110 ETP: usually in stock, 3–7 day lead time. OFE C101: 7–10 days due to lower stock volume. BeCu C17200: 10–14 days with material order + machining. Tellurium C145: 5–7 days, similar to C110. For large-volume copper orders (100+ parts), plan on 2–3 weeks including material procurement if not in stock.