Columbus Mckinnon m666a-p Screw Pin Anchor Shackle 21 Ton

Product Description

The COLUMBUS MCKINNON m666a-p is a heavy-duty alloy steel screw pin anchor shackle rated for a 21-ton working load limit (WLL). Built with a 5:1 design factor, it delivers strength approximately 50% greater than comparable carbon steel shackles and roughly 25% greater than super-strong shackle designs. The 1-3/8 inch body size suits demanding overhead lifting, rigging, and load-securing operations. Licensed riggers, crane operators, and rigging contractors are the primary installers of this hardware in industrial, construction, and marine environments.

This shackle is suited for use in heavy-lift rigging assemblies where high WLL and reliable pin retention are required. Typical applications include sling terminations, block-and-tackle rigging, load binders, and anchor-point connections on construction sites, shipyards, and industrial facilities. The screw pin design allows for quick assembly and disassembly in the field without special tooling.

Key Features

• 21-ton working load limit for high-capacity lifting and rigging
• 5:1 design factor provides a substantial safety margin over the rated load
• Alloy steel construction — approximately 50% stronger than comparable carbon steel shackles
• Approximately 25% stronger than super-strong shackle alternatives
• 1-3/8 inch body size suits large slings, hooks, and rigging hardware
• Screw pin design allows fast field assembly and disassembly without tools

Compatibility

Designed as a standard screw pin anchor shackle for heavy-duty lifting and rigging applications where a 21-ton WLL alloy steel shackle is specified.

Installation Notes

Installation should be performed by a qualified rigger following applicable ASME B30.26 rigging hardware standards. Always inspect the shackle, pin, and threads for wear, deformation, or corrosion before each use. Ensure the screw pin is fully seated and the pin shoulder contacts the shackle body before loading. Never apply side loads or point loads to the shackle bow in a manner inconsistent with its rated straight-pull orientation.

Technical Specifications

• Working Load Limit (WLL): 21 tons
• Design Factor: 5:1
• Body Size: 1-3/8 inches
• Material: Alloy Steel
• Pin Type: Screw Pin
• Shackle Style: Anchor (Omega)

Standard Information

• Brand: COLUMBUS MCKINNON
• Manufacturer Part Number: m666a-p