Clevis vs Shackle: What Sets These Connectors Apart

Clevis fasteners and shackles look remarkably similar at first glance. Both feature a U-shaped body closed by a removable pin, and both are designed to connect components in mechanical or rigging assemblies. However, this surface-level resemblance leads to frequent confusion on the job site, confusion that can result in the wrong hardware being used in a critical lifting application.

The distinction is vital: shackles and clevises are engineered for fundamentally different service conditions. Shackles are purpose-built rigging connectors, manufactured to meet strict consensus standards for overhead lifting. Clevises are general-purpose mechanical fasteners used in linkages, towing, and structural connections.

This guide explains the design, ratings, and appropriate applications for each to help riggers, safety managers, and engineers make informed decisions.

Safety & Use : This article is for educational awareness. Final gear selection must always follow the manufacturer’s Working Load Limit (WLL), site-specific rigging procedures, and applicable OSHA/ASME standards.

What Is a Clevis?

A clevis is a U-shaped mechanical fastener consisting of two parallel "ears" or "tangs" joined at one end, with aligned holes at the open end to accept a pin. The defining characteristic of a clevis is that it is typically an integrated component of a larger mechanical assembly rather than a standalone piece of rigging hardware.

Common Clevis Applications

Clevises are semi-permanent pivot points designed to transfer loads in a specific, predictable direction (usually in-line or in shear). Common uses include:

• Agricultural Equipment : Clevis hitches on tractors for towing trailers.
• Hydraulic Cylinders : Pivot mounts that allow actuators to move through a specific arc.
• Piping Supports : Clevis hangers used to suspend horizontal pipe runs from overhead beams.
• Marine Hardware : Connecting standing rigging on sailboats to fixed chainplates.

Clevis Ratings

Most importantly, a general-purpose clevis is not rated for overhead lifting. While it may have a "tensile strength" rating, it lacks the verified Working Load Limit (WLL) and the 5:1 design factor required for rigging hardware.

What Is a Shackle?

A shackle is a U-shaped metal connector specifically designed and tested as a standalone link in rigging and lifting assemblies. Unlike a generic clevis, a rigging shackle is a traceable safety component.

The Rigging Standard: ASME B30.26

In the United States, shackles used for lifting must comply with ASME B30.26. This standard requires that the shackle body be permanently marked with:

1. The manufacturer’s name or trademark.
2. The Working Load Limit (WLL).
3. The nominal size.

Holloway Houston stocks a wide variety of Crosby Shackles that meet or exceed these requirements, providing the traceability needed for industrial safety audits.

Key Differences : Clevis vs. Shackle

Shackle Types and Configurations

Because shackles are designed for the dynamic world of rigging, they come in several body and pin styles:

1. Body Shapes

• Anchor Shackles (Bow Shackles) : The rounded "O" shape allows for multiple sling legs to be attached to the bow without crowding. This is the standard for most Rigging and Lifting Slings.
• Chain Shackles (D-Shackles) : A narrower, "D" shaped body designed primarily for straight, in-line pulls.

2. Pin Styles

• Screw Pin : The pin threads directly into the shackle ear. Ideal for temporary applications where the shackle is frequently removed.
• Bolt-Type : Uses a bolt, nut, and cotter pin. This is the most secure option for long-term installations or applications where the pin may rotate during the lift. HHI recommends the Crosby G-2130 for these scenarios.

When to Use Which?

Use a Shackle when:

• You are performing an overhead lift.
• You need a connector with a verified, traceable Working Load Limit (WLL).
• You are connecting multiple slings to a single hook.
• The connection needs to be disassembled and reassembled frequently.

Use a Clevis when:

• You are building a mechanical linkage (like a steering rod).
• The connection is a permanent part of a machine's assembly.
• The application is for low-stakes towing or structural support (like a pipe hanger) rather than lifting.

Inspection and Maintenance

Both connectors require inspection, but the criteria for shackles are much stricter due to the risks involved in lifting.

• Shackle Inspection : Look for cracks, nicks, gouges, or any signs of "heat damage." If the WLL marking is missing or unreadable, the shackle must be removed from service immediately per ASME standards.
• Clevis Inspection : Check for pin wear and "hole elongation" (where the circular holes become oval-shaped due to stress). Ensure cotter pins are not corroded or broken.

Shop Certified Rigging Hardware at Holloway Houston

Don't gamble with unrated hardware. Holloway Houston provides a full range of high-quality, traceable rigging connectors to ensure your site stays compliant and your crew stays safe.

• Browse All Crosby Shackles
• Explore Rigging Hardware & Fittings
• View Synthetic and Wire Rope Slings

Need help choosing the right connector? Request a Quote or call our technical team at 713-675-3900.