Official Answer
Answer
Beryllium Copper (CuBe) Alloy 25 (UNS C17200) is the highest-strength copper-based alloy. It is used for spiral rings in explosive environments (non-sparking) and in sensitive electronics or MRI machines (non-magnetic, μ < 1.001). CuBe rings can be age-hardened to achieve tensile strengths up to 1400 MPa, comparable to many steels. However, its Modulus of Elasticity $E$ is lower ($≈$ 125 GPa compared to 200 GPa for steel), meaning CuBe rings provide less radial tension for the same thickness. Design engineers must also account for the toxicity of beryllium dust during any subsequent machining, though the finished ring is safe for use.
