A shackle is a U-shaped piece of metal secured with a screw pin bolt across the opening, or a hinged metal loop secured with a quick-release locking pin mechanism. They are used as a connecting link in all manner of rigging systems, from boats and ships to industrial crane rigging. D-Shackles range from 0.5t to 25t. D-shackles are narrow shackles shaped like a loop of chain, usually with a pin or threaded pin closure. D-shackles are very common and most other shackle types are a variation of the D-shackle. The small loop can take high loads primarily in line. Side and racking loads may twist or bend a D-shackle. Key Features: Used as connecting links in rigging systems The large shape of the loop means they are used in conjunction with webbing slings Forged, quenched and tempered with alloy pin Our screw pin shackles meet the performance requirements of federal specification RR-C-271D Type IVA, Grade A, Class 2 Marked with manufacturers mark, size, ID mark, CE and W.L.L