About 17510|Beryllium copper (CDA 175, 96.7% copper, 2% beryllium, 0.3% cobalt). Precipitation-hardens to extremely high strength (up to 200 KSI tensile) while retaining good conductivity. The strongest copper alloy commercially available. Used for springs, electrical connectors, non-sparking tools, mold inserts, and resistance welding electrodes. Machine it in the annealed condition — it’s reasonable before aging. After age-hardening it’s very tough on tools. Safety note: beryllium dust is highly toxic. Requires proper ventilation and dust collection during machining. Never dry-machine or grind without respiratory protection. Compare to
C110 (much weaker, safe to machine) and 17-4 PH stainless (similar hardening concept, no toxicity concern).