Rigging Shackles Explained: Types, Safety, and Selection Guide

When it comes to lifting and rigging operations, shackles are among the most vital components in your toolbox. Whether you're hoisting a load with a crane, towing heavy equipment, or setting up a long-term rigging system, the right shackle provides a secure and safe connection between rigging gear and the load.

This guide will explain the main types of rigging shackles, their best uses, and how to choose the right one for your specific job—helping you lift more safely and efficiently.

A rigging shackle is a metal connector used to join lifting slings, chains, ropes, or hardware to loads or anchor points. Most shackles have a U-shape with a removable pin, allowing for quick attachment and detachment. Shackles are utilized across various industries, including construction, marine, transportation, utilities, and manufacturing.

Despite their small size, shackles carry great responsibility—and improper use can lead to load failure, damage, or injury. That’s why knowing the correct type and how to use them is so important.

All rigging shackles are made up of two essential parts—each playing a vital role in strength, stability, and safety.

The body forms the main U-shape of the shackle and is available in either a bow (rounded) or D (narrow) shape.

Provide more space and flexibility for multi-directional loads, making them ideal for multi-leg slings or bridle hitches.

Also known as (chain shackles), are more effective for straight-line pulls, focusing the force along the centerline for increased strength in that direction.

The choice between these two options depends on how your load will be applied and whether it might shift during lifting.

The pin links the two arms of the shackle body and is available in various types.

Quick and simple to install by hand—ideal for temporary use.

Includes a nut and cotter pin—perfect for permanent or vibration-intensive applications.

Secured with a cotter pin—used in towing and non-lifting applications.

Each pin type influences setup speed, security level, and how resistant it is to loosening during use. Regardless of the type, the pin must be properly seated and secured to avoid accidents during lifting.

Anchor shackles, also called bow shackles, have a wide, rounded “O” shape. This extra width lets you attach multiple things inside the shackle and supports loads coming from different directions—perfect for situations where loads might shift or come from various angles.

They’re commonly used in multi-leg sling hitches, crane rigging, and complex lifts, where flexibility is essential. The rounded body helps prevent binding or damage when multiple slings or rigging lines are attached.

•  Bridle lifts and basket hitches.
•  Unpredictable or moving loads.
•  Lifts with angled or side forces.

The broader shape distributes the load differently than a D shackle and can be slightly less efficient in true vertical lifts.

Chain shackles, or D shackles, have a narrow profile that forms a “D” shape. The load is centered directly between the side walls and pin, which makes them great for inline pulls or vertical lifts.

They are most effective when force is applied in a single direction, such as connecting a sling to a fixed eye or lifting point. The compact design provides higher strength for straight lifts but has less tolerance for angled forces.

•  Vertical or straight-line lifts
•  Chain-to-chain or sling-to-sling connections
•  Controlled and predictable loads

These shackles are not designed for angular or multi-leg rigging. Side loading can weaken the shackle and increase the risk of failure.

Screw pin shackles feature a threaded pin that easily screws into the shackle body. This design allows for quick installation and removal, making it ideal for short-term projects or rigging that needs to be disassembled often.

You’ll often see screw pin shackles on construction sites, during machinery moves, or in any environment where rigging setups frequently change. Their simplicity and quick installation are convenient, but you must make sure the pin stays tight—especially in situations where vibration could loosen it.

•  Temporary or mobile lifts
•  Quick rigging setups
•  Situations where tools aren’t handy

Pins may loosen over time from vibration. Always double-check their tightness and inspect them between lifts.

Bolt-type shackles use a bolt with a nut and cotter pin, making them significantly more secure than screw pins. They’re designed for long-term or critical lifting operations where safety must not be compromised.

The multi-part pin system prevents accidental loosening, even in high-vibration conditions. This makes bolt-type shackles the top choice for permanent rigging, crane lifts, and overhead loads that remain rigged for long periods.

•  Long-term or permanent rigging points
•  High-safety environments (e.g., crane lifts)
•  Applications with heavy vibration or movement

They take longer to install and need tools, but the extra safety is worth it for critical applications.

Round pin shackles feature a smooth, non-threaded pin secured by a cotter pin. This design allows some rotational movement, which can be useful in towing or tie-down situations where slight shifting is expected.

They're less common in overhead lifting but are widely used in transportation and for anchor points, especially where loads are static or moderate in weight.

•  Light to moderate pulling or towing
•  Load restraint setups
•  Anchor points in non-critical lifting

Not typically rated for dynamic or overhead lifting. Use caution and always verify load requirements.

Ask yourself the following when selecting a shackle:

•  Use a D shackle for straight-line lifting.
•  Use a bow shackle for angled or multi-sling applications.

•  Temporary rigging → Screw pin
•  Long-term or permanent → Bolt-type

•   Use galvanized shackles for outdoor or marine conditions.
•   Use alloy steel shackles for heavy-duty indoor industrial work.

•   Always check the stamped WLL and never exceed it.
•   Select shackles that meet or exceed your lift capacity needs.

Using shackles safely involves more than just selecting the right type—it also includes regular inspections, proper handling, and following rigging standards. Here are essential safety tips to keep every lift secure and compliant.

1. Use only rated shackles that meet or exceed ASME B30.26 standards and clearly display Working Load Limits (WLL), size, and manufacturer identification.
2. Inspect before each use. Check for signs of wear, corrosion, cracks, bent parts, or elongated pinholes. Damaged shackles must be taken out of service immediately.
3. Verify that the pin is fully seated and secure. For screw pin shackles, always hand-tighten completely and do not back off the pin to align it with the load. For bolt-type shackles, ensure both the nut and cotter pin are properly in place.
4. Avoid side loading or off-axis forces. Shackles are designed for straight-line pulls. Applying force at an angle—unless rated for it—can significantly reduce strength and cause failure.
5. Never substitute pins with improvised options. Always use the original manufacturer-supplied pin for each shackle. Mixing pins, even from the same brand, can weaken strength ratings.
6. Be aware of environmental factors. Extreme temperatures, saltwater, and chemical exposure can cause metal to deteriorate over time. In severe conditions, increase inspection frequency and consider using stainless or galvanized shackles.
7. Follow a documented inspection schedule. In addition to pre-use checks, conduct frequent and periodic inspections based on how often the shackle is used. Heavy-use shackles may need daily checks; occasional-use shackles should be inspected at least once a month.

By following these guidelines, riggers minimize the risk of accidents and ensure compliance with industry safety protocols—helping to protect both people and property during lifting operations.

Choosing the right shackle isn't just about convenience — it’s about safety, compliance, and successful lifts. Whether you’re handling temporary field work or installing a permanent rigging point, selecting the correct shackle type for your application is essential.

At Empire Rigging, we offer a wide range of load-rated, ASME-compliant shackles for every jobsite and rigging challenge. From screw pin anchor shackles to heavy-duty bolt-type chain shackles, we have the equipment to get the job done right.