US Type Screw Pin Chain Shackle 210
US type screw pin chain shackle 210 aka screw pin d shackle or dee shackle, features its “D” shape, shackle’s body is made from high tensile carbon steel(C1045), and the shackle pin is premium quality alloy steel(40Cr), generally meet to US Fed.Spec.RR C 271 & ASME B30 26.
Proof load at 2 times the Working Load Limit(W. L. L). Minimum Breaking Strength(M.B.S) at 6 times (drop forged & heat treatment) or 4 times (drop forged but non heat treatment) the W.L.L. Check this link about the heat treatment process