A drop forged, carbon steel shackle with an eye bolt which has metric coarse threads at one end. Please specify Ungalvanized (Black) or Galvanized shackles is required. Ungalvanized. Size: Body dia: 16mm, Opening: 32mm, Screw Pin Thread: M20, Clear Length: 54mm, Pin dia: 20mm, S.W.L: 1ton.