CM Super Strong Shackles

CM Super Strong shackles are Columbus McKinnon’s carbon-type anchor shackles, forged from micro-alloy steel and rated 17 to 50% stronger than comparable-sized carbon shackles. Every screw pin and bolt type Super Strong shackle carries a 6:1 design factor, an alloy quenched and tempered pin, and permanent working load limit (WLL) and traceability markings on the body. CM states they meet the dimensional requirements and exceed the performance requirements of Federal Specification RR-C-271, and that they show major deformation before failure. CM makes them in the USA.

Galvanized Finish

Every CM Super Strong shackle we list here is galvanized. CM rates galvanizing as its best corrosion protection of any finish it offers, so these shackles are a good fit for outdoor, wet and job-site rigging where bare steel would rust.

Screw Pin vs. Bolt Type Anchor Shackles

Anchor (bow) shackles have a rounder body than chain shackles, so they can take side loading and multiple connections. The pin style is the main choice:

• Screw pin anchor shackles (CM M6xxG) have a threaded pin that comes out fast, which makes them the better choice when you connect and disconnect often. Mouse the pin when it could back out.
• Bolt type anchor shackles (CM M8xxG) use a bolt, nut and cotter pin. This is the most secure pin setup and holds up against axial and torsional loads. Use them for semi-permanent or long-term rigging where the pin stays in place.

How to Choose a Size and WLL

Shackle size is the diameter of the bow stock, from 1/4″ (3/4 ton) up to 2″ (35 tons). Start with the heaviest load the shackle will see, including sling angle and any side loading, then pick a shackle whose rated WLL meets or beats it. Never exceed the WLL stamped on the shackle. Check that the pin and jaw fit your sling eye, hook or hoist ring, and inspect every shackle before each use per ASME B30.26. The chart below lists the CM part number and WLL for each size in both pin styles.

Buy CM Super Strong Shackles from Slings Unlimited

Slings Unlimited is a veteran-owned rigging distributor based in Augusta, Georgia. Most items ship within 24 to 48 hours from our primary shipping facility in Georgia, and each order confirmation comes with a tracking number. Need special testing or certification, a powder-coated or self-colored finish, or a size not listed? CM can provide testing and certification if you ask when you order. Contact us or call 706-750-9099 for a quote.

CM Super Strong Shackle Size Chart

• 1/4″ (0.75 ton WLL): screw pin M646G, bolt type M846G
• 3/8″ (1.5 ton WLL): screw pin M648G, bolt type M848G
• 1/2″ (3 ton WLL): screw pin M650G, bolt type M850G
• 5/8″ (4.5 ton WLL): screw pin M651G, bolt type M851G
• 3/4″ (6.5 ton WLL): screw pin M652G, bolt type M852G
• 7/8″ (8.5 ton WLL): screw pin M653G, bolt type M853G
• 1″ (10 ton WLL): screw pin M654G, bolt type M854G
• 1-1/8″ (12 ton WLL): screw pin M655G, bolt type M855G
• 1-1/4″ (14 ton WLL): screw pin M656G, bolt type M856G
• 1-1/2″ (20 ton WLL): screw pin M657G, bolt type M857G
• 1-3/4″ (30 ton WLL): screw pin M677G, bolt type M877G
• 2″ (35 ton WLL): screw pin M658G, bolt type M858G

WLL and part numbers are from Columbus McKinnon’s Super Strong Anchor Shackles catalog (CMSB-1218). All sizes shown are galvanized.