SOCKET CBL 3/4 G417|Crosby’s spelter sockets are made of forged steel, and have an efficiency rating of 100%, based on the catalog strength of the wire rope. The ratings are based on recommended use with 6 x 7, 6 x 19, or 6 x 37, IPS or XIP (EIP), XXIP (EEIP), RRL, FC or IWRC wire rope.