Lifting Hooks Guide: Types, Ratings & Inspection

Every rigging system ultimately transfers load through a hook. Whether installed on an overhead crane hoist or integrated into a chain sling assembly, the hook is the component that directly supports the load. Selecting an unsuitable configuration, exceeding the Working Load Limit (WLL), or neglecting inspection requirements can introduce risk before lifting begins.

Lifting hooks are manufactured in multiple designs to match specific connection methods, load orientations, and operational demands. Performance ratings are established through engineered design, material strength, and proof testing. Ongoing serviceability depends on routine inspection to identify deformation, wear, cracking, or other damage that could affect structural performance.

Industrial operations commonly rely on forged alloy hooks from manufacturers such as Crosby and Yoke, widely used across Grade 80 and Grade 100 lifting systems. Suppliers including Holloway Houston support these product lines with application-specific selection and availability for field operations.

Safety Note

Equipment selection, load rating verification, and lift planning must always follow sling identification tags, manufacturer specifications, and site-specific rigging procedures.

Types of Lifting Hooks

Lifting hooks are not interchangeable. Each type is engineered for a specific connection method, load geometry, or operating condition. Choosing the right hook is one of the most basic and critical rigging decisions you will make.

Hoist Hooks (Crane Hooks)

A hoist hook, also called a crane hook—hangs from the block on an overhead crane, mobile crane, or chain hoist. It is the primary load-bearing connection point between the hoisting mechanism and the rigging below.

• Design : Typically forged steel, heat-treated, and equipped with a safety latch to prevent slings from slipping out of the bowl during slack conditions.
• Mounting Styles : Shank hooks (which thread into the crane block with a nut) and swivel-top hooks (which allow rotation).
• Application : Their sole job is vertical load support. They are never intended to be shortened, modified, or used as tie-down anchors.

Sling Hooks & Grab Hooks

Sling hooks attach to the ends of chain slings, wire rope slings, or synthetic sling assemblies. They connect the sling directly to the load by fitting over a lifting lug, trunnion, or similar attachment point.

Grab hooks are a related subtype with a narrower throat opening designed specifically to engage individual chain links for shortening or securing a chain. The modern cradle-style grab hook better supports the engaged chain link, often preventing any reduction in the sling's rated capacity when used as intended.

Always match grades: A Grade 80 sling hook is strictly rated for Grade 80 chain, and Grade 100 for Grade 100. Mixing grades puts the entire assembly at risk.

Swivel Hooks

Swivel hooks incorporate a rotating element between the hook body and the attachment point, allowing the hook to turn without transmitting twist into the sling or hoist line above it.

• Positioning Swivel Hooks : Allow the rigger to orient the hook during connection but do not rotate freely under load.
• Bearing Swivel Hooks : Feature a ball bearing that enables full 360-degree rotation even while the hook is loaded under tension. If your load will spin or rotate, a true bearing swivel is required.

Eye Hooks

Eye hooks feature a solid closed eye at the top instead of a clevis pin or shank. The eye connects directly to a chain link, master link, or coupling link, making it a permanent or semi-permanent attachment.

Because the eye is welded or mechanically forged as part of the sling assembly, removing an eye hook typically means removing the entire sling from service. They are the right choice when a permanent connection is acceptable and field disconnection is unnecessary.

Sorting and Foundry Hooks

• Sorting Hooks : Also called lay-out or shake-out hooks, these feature an elongated, narrow throat designed to reach around flat plates, structural beams, and pipes. Common in steel service centers.
• Foundry Hooks : Designed with a wide, deep throat to fit over massive trunnions and handles on castings and molds. They are engineered for high-heat environments and are usually paired with chain slings rated for elevated temperatures.

Hook Ratings & Working Load Limits

Every lifting hook has a working load limit (WLL), the maximum load that the hook is rated to support under normal service conditions. The WLL is not a breaking strength; it is the load the manufacturer guarantees the hook can handle repeatedly with a built-in safety margin.

WLL Marking and Manufacturer Documentation

ASME B30.10 requires that hooks carry specific identification markings forged, cast, or die-stamped on a low-stress, nonwearing area of the hook.

• Manufacturer's identification.
• Rated load identification (WLL).

If these markings are illegible or missing, the hook must be removed from service until the rated load can be officially confirmed.

Design Factor Awareness

Hooks are manufactured with a "design factor"—the ratio between the hook's minimum breaking strength and its WLL. This provides a safety margin for dynamic loading, wear, and environmental variables. Riggers do not calculate the design factor in the field; they simply rely on the WLL, knowing the safety buffer is already built-in. Exceeding the WLL erodes that margin rapidly.

Latch Function and Rated Load

Safety latches retain slings and rigging components in the hook bowl during slack conditions. They are not load-bearing devices. While a damaged latch does not change the hook's structural WLL, it significantly compromises safety and is an immediate removal-from-service condition under ASME B30.10.

Hook Inspection & Removal Criteria

Regular hook inspection is a baseline requirement under both OSHA regulations and ASME standards. Every hook should be visually checked before each use and formally inspected on a scheduled basis.

Inspection Triggers for Removal from Service

• Cracks : Any crack, regardless of size or location, is an immediate removal condition. Welding or repairing a cracked hook without explicit manufacturer authorization is unacceptable.
• Throat Opening Increase : A measurable increase indicates overloading or accumulated fatigue. OSHA 1910.179 dictates removal for crane hooks with more than a 15% increase in excess of normal throat opening. ASME B30.10 defers to manufacturer recommendations.
• Twist or Bend : A hook twisted out of its original plane has been side-loaded. OSHA 1910.179 requires discard if there is more than a 10-degree twist from the plane of the unbent hook.
• Wear on Saddle/Load Pin : ASME B30.10 identifies wear exceeding 10% of the original section dimension of the hook or its load pin as a removal criterion.
• Damaged/Missing Latch : A safety latch that does not close fully, spring back, or is missing entirely requires removal.
• Illegible Markings : If you cannot read the manufacturer's ID or WLL, the hook cannot be verified and must be removed.
• Other Conditions : Evidence of heat exposure, unauthorized welding, grinding, or excessive pitting/corrosion all warrant immediate evaluation.

OSHA vs. ASME: Scope Awareness

OSHA 1910.179 applies specifically to overhead and gantry cranes. Its numeric thresholds (15% throat opening, 10-degree twist) are written for crane hooks. ASME B30.10 covers hooks used across multiple types of lifting equipment and often defers to the manufacturer’s specific thresholds. Knowing which standard governs your specific lift is essential.

Crosby and Yoke Lifting Hooks

Holloway Houston distributes industry-leading rigging hooks from Crosby and Yoke across multiple grades and configurations.

Crosby S-1317 SHUR-LOC Clevis Hooks

The Crosby S-1317 SHUR-LOC clevis hook is a Grade 100 model forged from quenched and tempered alloy steel.

• Features : Positive locking latch, individually proof tested at 2.5x WLL, and fatigue rated for 20,000 cycles at 1.5x WLL.
• Capacity :Capacity: Available in sizes from 6mm through 1 inch with working load limits ranging from 3,200 to 59,700 lbs.
• Advantage : The clevis connection allows it to be pinned directly to chain fittings without welding.

Crosby S-1316 SHUR-LOC Eye Hooks

Crosby S-1316 eye hook is the eye-type counterpart to the S-1317. It features the same Grade 100 alloy steel, positive locking latch, and rigorous proof/fatigue testing, but utilizes a solid eye connection for permanent mechanical attachment to a chain sling leg.

Yoke Grade 80 & Grade 100 Hooks

Yoke’s Grade 100 swivel self-locking hooks are a highly popular choice for assemblies where load rotation is a factor. They feature ball bearings for 360-degree rotation under load and undergo 100% magnaflux crack detection during manufacturing.

Note: Grade 100 hooks deliver approximately 25% higher working load limits than Grade 80 hooks of the identical physical size, making them ideal when space or weight is a constraint.

Get the Right Hardware for the Lift

Knowing the difference between hook types, respecting working load limits, and conducting rigorous inspections are the non-negotiable basics of safe rigging.

Are you looking to replace worn hardware or outfit a new sling assembly? You can browse our full inventory of rigging hooks, including Grade 80, Grade 100, clevis, eye, and swivel configurations.