Cube2 -- c1720 (cda172) beryllium copper is the most commonly used copper beryllium alloy. Compared with commercial copper alloy, it has the highest strength and hardness. Alloy C17200 contains about. When the hardness is close to Rockwell C45, the ultimate tensile strength of 2% beryllium can exceed 200 Ksi. At the same time, under the condition of complete aging, the conductivity is at least 22% IACS. C1720 also shows excellent stress relaxation resistance at high temperature. https://www.zegotawire.com/beryl...eryllium-copper-rod.html