What Is a Screw Pin Shackle?
A screw pin shackle is the most common type of shackle in lifting and rigging, and for good reason: it is simple, strong, and quick to connect and disconnect by hand. This guide explains what a screw pin shackle is, how it differs from other pin types, and when to use one.
What Is a Screw Pin Shackle?
A screw pin shackle is a forged U-shaped or bow-shaped connector whose pin screws directly into the threaded shackle body. The pin is tightened by hand or with a small wrench, closing the opening and securing the sling, chain or hook. Because there is no separate nut or cotter pin, it is one of the fastest shackles to rig.
Screw Pin vs Bolt Type Shackle
Screw pin: the pin threads into the body and tightens by hand. Quick to fit and remove, ideal for jobs that are rigged and de-rigged often.
Bolt type: the pin is a separate bolt secured with a nut and often a cotter pin. Better for permanent or long-term connections and heavy load cycles.
When to Use a Screw Pin Shackle
Use a screw pin shackle when the load direction may change, when the rig is set up and broken down frequently, or when speed matters. For a straight-line pull, a Dee style screw pin shackle is lighter; for multi-direction loads, a bow style is safer. See our US type bow shackle and US type Dee shackle.
Screw Pin Shackle Sizes and WLL
Shackle size is given by the pin diameter, and the working load limit (WLL) rises with it. Never exceed the WLL stamped on the body. For a full size-to-load reference, see our shackle size chart.
How to Inspect a Screw Pin Shackle
Before each lift, check that the pin threads fully and is snug, and that the body shows no bending, cracking, corrosion or stretching. A distorted shackle must be taken out of service.
FAQ
What is a screw pin shackle used for?
It connects slings, chains, ropes and hooks during lifting and rigging, especially where the rig changes frequently.
Can a screw pin come loose?
It can vibrate loose, so tighten it fully and check it before each lift. For permanent or vibrating loads, use a bolt type shackle with a cotter pin.
Is a screw pin shackle as strong as a bolt shackle?
For the same size and grade, yes. The difference is convenience and security, not rated strength.
Browse Our Shackles
SolidLink forges screw pin and bolt type shackles in carbon steel and stainless steel, with WLL marked and certificates available. Browse our shackles or contact us for a quote.
