Aufhauser C773 Nickel Silver 1/2 Lb RBCuZn-D (1/16", Blue) C773 Nickel Silver rods. (1/2 Lb) Braze welding alloy Meets AWS A5.8 Class RBCuZn-D For repair and rebuilding of worn and broken parts. Drills, grins, gears, pump impellers, roller bearing races. Named nickel silver due to the alloy's silvery apperance, does not contain silver.