Wire Rope Sling Types, Configurations and Working Load Limits

Wire rope slings connect loads to lifting equipment in construction, offshore, marine, and industrial operations. They are built from strands of high-carbon steel wire twisted into rope, then fabricated into sling assemblies with end fittings that attach to crane hooks, shackles, and load points. Choosing the right wire rope sling means matching the sling construction, configuration, and WLL to your specific load, environment, and lift geometry.

Holloway Houston manufactures and distributes wire rope slings in Houston, TX, with same-day quotes on in-stock sizes and custom fabrication for project-specific requirements.

Wire Rope Sling Configurations

Wire rope slings are available in five primary configurations. Each serves a different function in how the sling connects to the load and the lifting equipment.

Eye-and-Eye Single Leg Slings The most common configuration. A single rope with a Flemish eye or swaged eye at each end. Used in vertical, choker, and basket hitch applications. Eye-and-eye slings are the baseline configuration for most general industrial lifting.

Bridle Slings (Multi-Leg) Two, three leg bridle sling, or four single-leg slings joined at a master link. Used when the load has fixed lift points and must be kept level during the lift. The number of legs determines the WLL of the assembly - a two-leg bridle rated at 60° provides 1.73× the WLL of a single leg.

Cable-Laid Slings Multiple wire ropes laid together to form a single larger rope, then fabricated with end fittings. Cable-laid construction provides high flexibility and resistance to crushing on large-radius contacts. Common in heavy fabrication and structural applications.

Grommets (Endless Slings) A continuous loop of wire rope with no end fittings. Grommets wrap around a load or connect directly to a hook without a fitting. High strength-to-weight ratio and no fittings to inspect separately.

9-Part and Braided Slings Nine or more rope parts braided Load is distributed across multiple rope parts simultaneously. Used for extremely heavy loads where a single-part/ three-part sling would require impractically large diameter rope.

Wire Rope Sling WLL by Configuration and Hitch

Working Load Limit changes based on how the sling is used - not just what it is rated on the tag.

ASME B30.9 recommends a minimum 60° included angle for basket hitch configurations. Below 30°, choker efficiency applies even in basket configuration.

Wire Rope Construction Types

The construction code on a wire rope sling describes how many strands the rope has and how many wires are in each strand.

IWRC (Independent Wire Rope Core) provides 7.5% higher breaking strength than fiber core at the same diameter and resists crushing when the sling contacts sharp edges or tight radii. Fiber core provides greater flexibility where the sling must bend around contoured load surfaces.

ASME B30.9 Inspection Criteria

Wire rope slings must be inspected before each use under ASME B30.9 and OSHA 1910.184. Remove from service immediately if any of the following are observed:

• 10 or more randomly distributed broken wires in any rope lay, or 5 broken wires in one strand within one rope lay
• Wear of 1/3 of the original outer wire diameter in outside wires
• Kinking, crushing, birdcaging, or any distortion of the rope structure
• Evidence of heat damage - discoloration, loss of lubrication, melting of fiber core
• End fittings showing cracks, deformation, or wear reducing original diameter by more than 10%
• Missing or illegible WLL markings on the sling tag - remove from service until re-tagged by manufacturer

Periodic inspection: Wire rope slings in continuous or heavy service must be formally inspected at intervals established by a qualified person, with results documented and retained.

Sling Angle - Why It Changes Your WLL

The sling angle is the angle between the sling leg and the horizontal plane. As the angle decreases from vertical (90°), tension in each sling leg increases. This directly reduces the effective lifting capacity of the assembly.

Standards Reference

• ASME B30.9 - Slings: inspection, removal-from-service, and application requirements for wire rope slings
• OSHA 1910.184 - Slings: federal sling regulation for general industry; daily inspection and WLL compliance required
• OSHA 1926.251 - Rigging Equipment for Material Handling: construction industry equivalent of 1910.184
• ASME B30.26 - Rigging Hardware: covers end fittings, shackles, and hooks used with wire rope slings