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Copper Alloy

C172 Beryllium Copper

C172 beryllium copper is the strongest copper alloy available, reaching about 1300 MPa tensile and 40 HRC after age hardening, while retaining useful 105 W/m·K conductivity and non-magnetic, non-sparking behavior. That rare combination of spring-grade strength and conductivity is why it commands a 4.5/5 cost and careful handling.

How C172 Beryllium Copper machines

Rated 3/5. It machines best in the soft (solution-annealed) condition before aging, then is precipitation-hardened to final strength. The critical caution is health, not tooling: machining, grinding, or any operation generating beryllium-bearing dust requires enclosed dust control and respiratory protection.

Manufacturing & processing

Processed by CNC, forging, and sheet forming, typically formed soft then age-hardened around 315 C to develop full strength. Heat treatment is what unlocks its 1300 MPa tensile. It solders and brazes well for electrical use and is non-magnetic, suiting sensitive instrument work.

Typical applications

The go-to for high-cycle springs, electrical connectors and contacts needing strength plus conductivity, non-sparking tools for explosive atmospheres, and plastic injection mold cores where its conductivity speeds cooling. Also used in undersea, oil-and-gas, and aerospace hardware needing strength without magnetism.

When to choose it

Reach for C172 when no other copper meets the strength: it roughly triples C510 phosphor bronze's yield while staying conductive and non-sparking. If you only need moderate spring strength or conductivity, cheaper C510 or C145 avoid the cost and the beryllium dust handling burden entirely.

Suitable surface finishes

Common finishes for C172 Beryllium Copper: nickel plating, chrome plating, electropolishing, brushed. Use the finish selector →

FAQ

Is beryllium copper dangerous to machine?
The solid part is safe to handle. The hazard is inhaling beryllium-containing dust or fume from machining, grinding, or welding, which can cause chronic lung disease. Work it with local exhaust, wet methods or enclosed dust collection, and respiratory protection per occupational limits. Finished parts pose no inhalation risk.
Why is C172 so much stronger than other coppers?
It is precipitation-hardenable. Aging the solution-treated alloy precipitates beryllium-rich particles that pin dislocations, pushing tensile to about 1300 MPa and 40 HRC, far above C510's 470 MPa. No other commercial copper alloy reaches this strength while staying conductive and non-magnetic.
Should I machine C172 before or after age hardening?
Usually before. Machine in the soft solution-annealed temper, then age-harden to final strength, which also minimizes tool wear and distortion. Light finishing after aging is possible but slower and generates the same beryllium dust precautions. Account for minor dimensional change during the aging step.

Property values are typical/nominal for early guidance and vary by temper, grade, supplier and heat treatment. Confirm critical specs against a certified datasheet or with an mfgiq engineer.