Shackles are manufactured to several standards which all have different dimensions.
The recognised standards are:
The style of shackle to be used will depend on the intended application. Bow shackle – can be used within an angle of up to 45⁰ from vertical on the bow. D shackle – only suitable for use ‘in line’
These then have different pin fittings, typically
Shackles are rated to a Working Load Limit (WLL)