What Is a Latch Hook in Lifting and Rigging?

On a working site, the component most likely to be overlooked in a pre-lift check is not the chain or the shackle. It is the latch on the hook: the spring-loaded mechanism that stops the sling from walking off the bill under load. When it fails, it rarely announces itself in advance.

A latch hook is one of the most widely used hook types in UK industrial lifting. It is found on chain slings, hoist assemblies, and crane rigs across construction, warehousing, and heavy manufacturing. 

Despite its prevalence, it is frequently confused with self-locking hooks, and the difference between the two is not academic. It determines whether the hook is appropriate for the application.

What Is a Latch Hook?

A latch hook is a lifting hook fitted with a spring-loaded latch that closes across the throat opening. When a sling, shackle, or master link is placed into the hook, the latch is pushed aside by the incoming component and snaps back behind it. No manual closing action is needed. 

To remove the attachment, the operator depresses the latch inward, compresses the spring, and clears the throat.

The latch does not lock. It is held in the closed position by spring tension alone, which is sufficient under normal operating conditions to retain the sling in place.

This is the defining difference from a self-locking hook. A self-locking hook engages an internal mechanical lock the moment the load is applied. That lock cannot be released until the weight comes off and the mechanism is manually disengaged. A latch hook relies on spring pressure; a self-locking hook is mechanically constrained by the load itself.

Both types comply with EN 1677, the European standard governing lifting components. Latch hooks are covered by EN 1677-2 for Grade 8 and EN 1677-5 for Grade 10. Self-locking hooks are covered by EN 1677-3.

How a Latch Hook Works

The hook body is forged from high-tensile alloy steel (Grade 8 or Grade 10, depending on the required WLL), and the spring-loaded latch is fitted to the bill, sitting across the throat opening. A rigger dropping a master link into the hook pushes the latch aside on entry; it springs closed as the link sits in the hook's bowl.

Under load, the suspended weight bears against the hook body's interior curve. The latch is not rated to bear the suspended load. It is a retention device: its job is to prevent the sling from backing out of the throat if tension is briefly lost. It is not there to carry the load if the hook fails. 

That distinction matters during inspection. A hook body in good condition with a worn or sluggish latch is not serviceable.

Types of Latch Hook Used in Industrial Lifting

Eye-Type Latch Hook

The eye-type latch hook has a fixed eye at the top for connection to a shackle, master link, or hoist ring. It is the standard configuration for single-leg chain slings and general-purpose overhead lifting. Because the eye does not rotate, these hooks work best where the load orientation is consistent, and the lift is straightforward vertical.

Clevis-Type Latch Hook

A clevis-type latch hook uses a pin-and-bracket fitting at the top rather than a fixed eye. The hook articulates slightly in the plane of the clevis, which reduces side-loading where two or more sling legs pull at angles rather than straight down. Clevis hooks are the common choice on two-leg and four-leg chain sling assemblies for this reason.

Swivel Latch Hook

A swivel latch hook incorporates a bearing at the top connection point, allowing the hook to rotate freely (up to 360 degrees in some configurations) under full load. This prevents rotational twist from accumulating in the sling legs when loads spin or need to be repositioned during the lift. This is a common requirement when setting structural steel components into position.

Grab Hook with Latch

A grab hook has a narrow throat profile designed to engage directly onto a specific chain link rather than accept a sling or shackle. Grab hooks with latches are used to shorten sling legs or create a choke arrangement on the chain. The latch stops the hook from releasing the link during load application, which is particularly important in dynamic or multi-leg setups where load distribution shifts.

Latch Hook vs Self-Locking Hook: Which to Specify

For routine chain sling work, including lifting machinery, structural fabrications, and production components in a controlled environment, a latch hook provides adequate retention. The spring mechanism is reliable under normal conditions, the hook is quick to rig and de-rig, and replacement components are widely available.

Self-locking hooks are the correct specification when the load may go slack mid-lift, when the sling could contact a surface and momentarily lose tension, or when the consequences of accidental disengagement are severe. 

Offshore lifts, suspended access platforms, confined-space operations, and any lift where the load path is unpredictable are the situations that call for the mechanical certainty of a self-locking design.

LOLER Requirements and Inspection

Under LOLER 1998, every lifting accessory including individual hooks, is lifting equipment in its own right. A latch hook on a chain sling has its own examination interval, its own marking requirements, and its own entry in the thorough examination record. 

It is not covered by the examination of the chain or the sling assembly.

The HSE's 2024/25 statistics recorded 59,219 RIDDOR-reportable injuries to employees across Great Britain, with work-related injury and ill health costing an estimated £22.9 billion. 

Equipment inspection failures, specifically worn latches and fatigued springs that pass a visual glance but fail under load, appear regularly in the incident categories that contribute to those figures.

LOLER requires thorough examination of lifting accessories at intervals not exceeding six months. For latch hooks, a competent person should check each of the following:

1. Hook body. Examine for cracks, surface deformation, and corrosion. Check the throat opening against the manufacturer's discard dimension; a widened throat reduces the hook's capacity to retain the sling under load.

2. Latch spring. Close the latch and release it. A latch that does not snap back firmly under its own spring tension is not fit for service. This is not a marginal condition. A sluggish latch will fail to close when it matters. Replace the hook or obtain a manufacturer-approved latch kit.

3. Latch pin. Check for wear or lateral play. A pin that moves by more than a fraction allows the latch to open unintentionally under vibration or incidental contact.

4. Grade markings. Grade 8 hooks carry the marking "8" or "80" on the body. Grade 10 hooks carry "10" or "100". If these markings are illegible, the hook must be withdrawn from service. The marking is not administrative. It is the only field verification of the hook's rated capacity.

Selecting the Right Latch Hook for a Chain Sling

Grade Compatibility

A Grade 8 hook must be paired with a Grade 8 chain. A Grade 10 hook with a Grade 10 chain. The weakest component in any assembly sets the WLL for the whole. Fitting a Grade 8 hook to a Grade 10 chain does not cause a physical problem with the connection, but it downgrades the entire sling to Grade 8 capacity and invalidates the Grade 10 assembly certification. That assembly will not pass a LOLER examination as a Grade 10 unit.

Chain Size Compatibility

Every latch hook is designed for a specific range of chain diameters. The throat geometry is engineered for a particular link profile. Forcing a 10 mm chain into a hook rated for an 8 mm chain stretches the throat and creates a risk of deformation under load. Select the hook size that matches the chain diameter in the sling specification, not the nearest available size.

Configuration

For a single-leg sling on a straightforward vertical lift, an eye-type latch hook is the standard choice. For multi-leg assemblies where the legs pull at angles, a clevis hook reduces the side-loading at the connection point. For loads that rotate or need to be repositioned during the lift, a swivel latch hook stops twist from accumulating in the sling legs.

FAQs

Can a latch hook be used for overhead lifting? 

Yes, provided it is manufactured to EN 1677-2 (Grade 8) or EN 1677-5 (Grade 10), correctly sized for the chain, and in good working order. The latch must be inspected before every lift, not just at the six-monthly thorough examination.

What is the difference between a latch hook and a safety hook? 

In UK lifting practice, the terms are often used interchangeably. Both refer to a sling hook with a spring-loaded latch. Where confusion arises, it is usually because some suppliers apply "safety hooks" to self-locking hooks as well. Check the EN 1677 sub-standard: EN 1677-2 or -5 indicates a spring latch; EN 1677-3 indicates a self-locking.

How often does a latch hook need to be inspected? 

Thoroughly examined by a competent person every six months under LOLER 1998, and visually checked by the operator before every single lift. These are separate obligations. One does not substitute for the other.

Can I replace just the latch spring rather than the entire hook? 

Only with a manufacturer-approved replacement latch kit for that specific hook model. Substituting a latch spring from a non-compatible source voids the hook's certification. After any latch repair, the hook must be re-examined before returning to service.

When should a self-locking hook replace a latch hook? 

When the load may go slack mid-lift, when the sling could contact a surface and temporarily lose tension, or when accidental disengagement would have serious consequences: offshore work, suspended platforms, and confined spaces. In those situations, spring tension is not enough.

Choosing the Right Hook

A latch hook is the right tool for the majority of chain sling applications on UK sites. Specify the correct grade, match the throat geometry to the chain diameter, and maintain the latch mechanism to the standard required by the examination. Those three criteria determine whether the hook performs to its rated capacity throughout its service life.

When a lift's risk profile demands more than a spring latch can provide, a self-locking hook is the next step. Both types are available in Grade 8 and Grade 10, and both carry the same LOLER examination obligations.

Velebit Lifting supplies certified chain sling assemblies and lifting hooks across the UK, with full LOLER documentation included as standard. If you have a specific chain size, grade, and application in mind, contact the team directly. Most hook-and-sling specification queries are confirmed the same working day, so you can order with confidence rather than guesswork.