A mobile crane is only as effective — and only as safe — as the lifting accessories used with it. The crane itself may be perfectly maintained, rigged by a competent operator, and working within its rated capacity — but if the hook, chain, or sling connecting the load to the crane is incorrectly selected, inadequately rated, or insufficiently maintained, the lifting operation is compromised at its most critical interface: the connection between the machine and the load.
For crane operators, fleet owners, rigging teams, and the lifting managers responsible for their equipment, buying the right accessories is not merely a procurement exercise. It is a safety-critical decision that demands technical knowledge, regulatory awareness, and a disciplined approach to both selection and ongoing inspection. Getting it right protects your team, your loads, your clients, and your business. Getting it wrong — even once — can have irreversible consequences.
This guide provides a comprehensive overview of the main types of crane lifting accessories — hooks, chains, and slings — covering what each type is, how to select correctly, what the regulatory requirements are, and how to evaluate suppliers and manage accessories throughout their operational life.
Understanding the Regulatory Framework
Before exploring the individual accessory types, it is important to establish the regulatory context within which crane lifting accessories must be selected, used, and maintained in the UK.
LOLER — Lifting Operations and Lifting Equipment Regulations 1998
LOLER applies not just to the crane itself but to all lifting accessories used with it. Under LOLER, lifting accessories — defined to include hooks, chains, slings, shackles, eyebolts, and all other devices used to attach loads to lifting equipment — must be:
- Of adequate strength and stability for the purpose for which they are used
- Clearly marked with their safe working load (SWL)
- Subject to thorough examination before first use, after any exceptional circumstances, and at least every six months during normal use — or more frequently where risk assessment indicates
The records of thorough examination for lifting accessories must be maintained in the same way as those for the crane itself, and defective accessories must be withdrawn from service immediately.
PUWER — Provision and Use of Work Equipment Regulations 1998
PUWER complements LOLER by requiring that all work equipment — including lifting accessories — is suitable for the purpose for which it is used, maintained in a safe condition, and inspected at appropriate intervals by competent persons.
Supply of Machinery Safety Regulations and CE/UKCA Marking
Lifting accessories placed on the UK market must comply with the Supply of Machinery (Safety) Regulations and carry the appropriate conformity marking — currently the UKCA mark for products placed on the Great Britain market, or CE marking under the transitional arrangements still applicable. These marks confirm that the accessory meets the essential health and safety requirements of the applicable directives and standards.
When purchasing lifting accessories — whether from a UK supplier or internationally — verifying the presence and validity of the appropriate conformity marking is an essential first step. Accessories without valid conformity marking should not be purchased or used.
Crane Hooks: Selection, Grading, and Safety
The hook is the primary connection point between the crane’s lifting medium and the load or rigging assembly. Its correct selection and maintenance are fundamental to safe lifting.
Types of Crane Hook
Swivel hooks allow the load to rotate freely relative to the crane line — useful where loads may need to be rotated during the lift or where residual rotation in the wire rope could otherwise cause uncontrolled load movement. They incorporate a swivel bearing between the hook body and the attachment point.
Shank hooks are rigidly attached by a threaded shank to the crane’s hook block or bottom block assembly. They are the most common hook type on mobile cranes and provide a direct, fixed connection without rotational movement.
Clevis hooks attach via a pin and clevis arrangement rather than a shank, making them easier to replace and allowing for different attachment orientations. They are common in rigging applications and as lifting accessories independent of the crane’s integral hook arrangement.
Safety hooks — sometimes called snap hooks — incorporate a spring-loaded safety latch that prevents accidental disengagement of the load or rigging from the hook. All hooks used in lifting applications should incorporate a safety latch; hooks without functional safety latches must be withdrawn from service.
Hook Grades and Material Standards
Crane hooks are manufactured from alloy steel to specific grades and standards that define their mechanical properties — yield strength, tensile strength, and impact resistance. The relevant standards for crane hooks in the UK and Europe include EN 1677 (components for slings) and specific manufacturer standards for hooks integral to crane equipment.
When purchasing replacement hooks or hooks as standalone accessories, verify that they are manufactured to the appropriate standard for the application and rated for the specific safe working load required.
Safe Working Load and De-rating
Every hook must be clearly marked with its safe working load in a manner that remains legible throughout its service life. The SWL marked on the hook reflects its capacity under the assumed load conditions — typically a directly downward pull — and may be de-rated for certain applications, such as off-centre loading or use in multi-leg configurations.
Never exceed the marked SWL on any hook, and never attempt to use a hook whose SWL marking has become illegible — such hooks must be withdrawn from service and either re-marked by a competent person or replaced.
Hook Inspection Criteria
Under LOLER, hooks must be subject to regular thorough examination by a competent person. Key inspection criteria include:
- Cracks — particularly in the throat, saddle, and shank areas of the hook, which are subject to the highest stress concentrations. Any crack is an immediate disqualifying defect.
- Deformation — hooks must be retired if the hook opening has increased by more than 10 percent from its original dimension, indicating permanent plastic deformation that compromises the hook’s structural integrity
- Twist — any visible twist in the hook body indicates overloading and requires immediate withdrawal from service
- Wear — excessive wear in the saddle or at the hook tip from repeated rigging contact reduces the effective cross-section and load-bearing capacity
- Safety latch function — the latch must close fully and spring back securely; a latch that does not function correctly renders the hook unsafe for use
Lifting Chains: Grade Selection, Capacity, and Care
Lifting chains are among the most versatile lifting accessories available — robust, abrasion-resistant, and suited to a wide range of temperature extremes and hostile environments that would rapidly degrade fibre slings. Their correct selection, however, depends on understanding the grading system and matching the chain grade to the application requirements.
Chain Grades and Their Meaning
Lifting chains are classified by grade — a number that reflects the chain’s minimum breaking force relative to its nominal diameter. Higher grade numbers indicate higher strength chains of the same physical dimensions.
Grade 8 (G8 or T8) is the most widely used lifting chain grade for general industrial and construction applications. Grade 8 chains offer an excellent combination of strength, toughness, and resistance to fatigue — making them suitable for the majority of lifting tasks encountered in mobile crane operations.
Grade 10 (G10 or T10) provides approximately 25 percent higher safe working load than Grade 8 chain of the same diameter — enabling users to achieve higher capacities with lighter chain assemblies. Grade 10 is increasingly specified in applications where minimising rigging weight is important or where the additional capacity of a larger Grade 8 chain would be disproportionate.
Grade 12 (G12 or T12) represents the current upper tier of commercially available lifting chain grades, offering approximately 50 percent higher safe working load than Grade 8 of equivalent diameter. Grade 12 is used in applications demanding the highest possible capacity from the minimum chain dimensions — particularly in automotive and precision engineering environments, though increasingly in general lifting applications as well.
Grade 4 and Grade 6 chains are not suitable for overhead lifting and must not be used as lifting accessories. These lower-grade chains — commonly found as general-purpose chains, tie-down chains, or anchor chains — are frequently misidentified as lifting chains and present a serious safety risk when used in lifting applications. Always verify the grade marking before using any chain in an overhead lifting application.
Chain Sling Configurations
Chains used as lifting accessories are typically assembled into chain sling configurations — single, two, three, or four leg arrangements with appropriate terminal fittings at each end. The safe working load of the assembled sling depends on the chain grade, diameter, number of legs, and the sling angle at which the legs operate.
Sling angle effects are one of the most frequently misunderstood aspects of chain sling selection. As the angle of a multi-leg sling increases from vertical, the tension in each leg — and therefore the load each leg must sustain — increases significantly. At a 60-degree sling angle, each leg carries approximately 15 percent more load than its direct calculation suggests; at 45 degrees, the increase is approximately 41 percent. Rigging teams must understand sling angle effects and select chain slings rated for the actual configuration they will be used in, not simply the total load weight.
Chain sling assemblies should be purchased from reputable, accredited suppliers and should be accompanied by a test certificate confirming the SWL of the complete assembly, the chain grade, the diameter, and the configuration. Assembling chain slings from individual components without proper testing and certification is not acceptable under LOLER.
Chain Inspection and Retirement Criteria
Regular inspection of lifting chains is essential for detecting wear, damage, and deformation before they compromise the chain’s load-bearing capacity.
Chains should be retired from service when:
- Any link shows visible cracks, nicks, or gouges — sharp notches in a chain link act as stress concentrators that dramatically reduce the link’s fatigue life
- Wear has reduced the link diameter by more than 10 percent of the original nominal diameter
- Any link is visibly bent, twisted, or elongated — indicating overloading or shock loading that has plastically deformed the chain
- The chain has been subjected to chemical attack — acids, alkalis, and certain industrial chemicals can significantly reduce chain strength without visible surface damage
- The chain has been subjected to excessive heat — heat from welding operations, fire, or high-temperature environments can anneal the chain steel and reduce its strength; heat-affected chains should be withdrawn from service regardless of their visual appearance
All lifting chains should be stored in a dry environment, coated with a light oil or chain dressing to prevent surface corrosion, and kept free from contact with chemicals that could cause hydrogen embrittlement or chemical attack.
Lifting Slings: Web, Round, and Wire Rope Varieties
Lifting slings are available in three principal types — web slings (flat woven textile), round slings (tubular synthetic fibre), and wire rope slings — each with distinct performance characteristics, application suitability, and inspection requirements.
Web Slings (Flat Woven Synthetic)
Web slings are manufactured from woven polyester or nylon webbing and are among the most widely used rigging accessories in construction and industrial lifting. Their key advantages include:
- Wide bearing surface — web slings distribute load across a broader contact area than chain or wire rope, reducing the risk of surface damage to sensitive or finished loads
- Lightweight and flexible — web slings are significantly lighter than chain or wire rope of equivalent capacity, reducing rigging weight and improving ease of handling
- Non-abrasive contact — suitable for use on finished or polished surfaces where chain or wire rope would cause scratching or marking
Web slings are colour-coded by load capacity according to EN 1492-1, with each colour representing a defined safe working load for the sling used in a vertical single-leg configuration:
- Violet — 1 tonne SWL
- Green — 2 tonnes SWL
- Yellow — 3 tonnes SWL
- Grey — 4 tonnes SWL
- Red — 5 tonnes SWL
- Brown — 6 tonnes SWL
- Blue — 8 tonnes SWL
- Orange — 10 tonnes SWL
As with chain slings, the rated capacity of a web sling is affected by the configuration in which it is used — choker hitches and wide-angle configurations reduce the effective SWL below the single-leg vertical rating.
Web slings must be inspected before each use and retired from service when:
- Cuts, tears, or abrasion damage are visible on the webbing
- The stitching at the eye or splice is frayed, broken, or pulled through
- Chemical damage — acid burns, bleaching, or stiffening — is apparent
- The colour-coded label is missing or illegible, preventing safe working load identification
- The sling has been subjected to heat damage — charring, melting, or discolouration indicating thermal exposure
Round Slings (Polyester Core Slings)
Round slings — sometimes called endless round slings or polyester core slings — consist of a polyester fibre core enclosed in a protective woven sleeve. Their circular cross-section allows them to adapt naturally to the shape of the load, distributing the lifting force evenly around the load contact point.
Key advantages of round slings include:
- High strength-to-weight ratio — round slings achieve very high safe working loads for their weight, making them valuable where rigging weight is a consideration
- Flexibility and conformity — the round profile adapts well to irregularly shaped loads and wraps naturally into basket or choker hitches
- Protective sleeve — the outer sleeve protects the load-bearing fibre core from surface abrasion and minor chemical contact while also providing visual indication of damage
Round slings are colour-coded by capacity according to EN 1492-2, using the same colour code as web slings for equivalent SWL ratings.
Round slings must be inspected before each use and retired when the outer sleeve shows cuts, abrasion damage, or burn marks that may have reached the inner core, or when the sling has been involved in a shock load or overload event.
Wire Rope Slings
Wire rope slings offer greater resistance to cutting damage and thermal exposure than textile slings and maintain their properties across a wider temperature range. They are suited to applications involving rough or abrasive load surfaces, high temperatures, or environments where textile slings would rapidly deteriorate.
Wire rope slings are manufactured to EN 13414, which specifies the required construction, splicing methods, and performance characteristics. They must be accompanied by a test certificate confirming their safe working load and construction details.
Wire rope sling inspection criteria closely mirror those for the crane’s own wire rope — inspecting for broken wires, kinking, corrosion, and splice integrity. Any wire rope sling showing significant broken wires, kinking, corrosion, or splice damage should be removed from service immediately.
Shackles, Swivels, and Other Terminal Fittings
Lifting accessories are connected to each other and to loads through a range of terminal fittings — shackles, swivels, master links, and lifting eyes — each of which must be rated, certified, and inspected with the same rigour as the primary sling or chain.
Shackles
Shackles are among the most frequently used connecting devices in crane rigging. They are available in two principal configurations:
Bow shackles (also called omega or round shackles) have a large, rounded bow that allows multiple sling legs or rigging elements to be attached simultaneously. They are the preferred configuration where load can be applied at an angle to the pin — bow shackles are designed to accommodate angular loading.
D-shackles (also called dee or chain shackles) have a narrower, D-shaped bow suited to direct in-line loading. They should only be used where the load is applied directly in line with the pin — angular loading on a D-shackle can significantly reduce its effective capacity.
Shackles are available in screw-pin and bolt-and-nut configurations. For crane rigging applications, bolt-and-nut shackles with a split pin through the nut are strongly preferred over screw-pin types — screw-pin shackles can loosen and unscrew under rotational load, allowing the pin to back out and the load to be released.
Inspection of Terminal Fittings
All terminal fittings should be inspected before each use for:
- Cracks, deformation, or damage to the body
- Wear at the pin and bearing surfaces
- Thread damage or corrosion on screw-pin shackles
- Legibility of the SWL marking
Fittings showing any of these defects must be withdrawn from service.
Buying Crane Accessories: Supplier Selection and Quality Assurance
The quality of lifting accessories is directly correlated with the quality of the supplier from whom they are purchased. In a market where price-driven procurement may lead buyers toward unverified or sub-standard products, the consequences of cutting corners on lifting accessory quality can be severe.
When selecting a supplier for crane lifting accessories, verify:
- LEEA membership — suppliers accredited by the Lifting Equipment Engineers Association meet defined standards of technical competence and product quality that provide meaningful assurance of accessory safety and compliance
- EN standards compliance — confirm that products are manufactured to the relevant European standards (EN 818 for chain, EN 1492 for textile slings, EN 13414 for wire rope slings, EN 1677 for components) and that this compliance is documented by the supplier
- CE or UKCA marking — all lifting accessories placed on the UK market must carry the appropriate conformity marking and be accompanied by the declaration of conformity
- Test certificates — every lifting accessory assembly should be accompanied by a test certificate confirming the safe working load, construction, standard of manufacture, and the results of proof load testing carried out before supply
- Traceability — quality suppliers maintain traceability records for their products — linking each item to its material batch, manufacturing records, and test results — that can be accessed in the event of a quality concern or incident investigation
Purchasing lifting accessories from unverified online sources, without accompanying documentation, CE or UKCA marking, or test certificates, is a serious safety and regulatory risk that no operator should accept regardless of the apparent cost saving.
Maintaining a Lifting Accessories Register
Under LOLER, operators are required to maintain records of all lifting accessories in use — recording their identification, rated capacity, date of last thorough examination, and the outcome of that examination. A lifting accessories register — whether maintained in a physical logbook or a digital fleet management system — provides the administrative foundation for this compliance requirement.
The register should record each item’s:
- Unique identification number (most accessories should be individually numbered or tagged)
- Type, size, grade, and safe working load
- Date of manufacture or purchase
- Date and outcome of each thorough examination
- Any defects identified and actions taken
- Date of retirement from service, if applicable
Maintaining a complete and current accessories register is not merely a compliance exercise — it is an operational discipline that ensures no unexamined or overdue accessory enters service undetected, and that the complete maintenance history of each item is available when needed.
Final Thoughts
Lifting accessories — hooks, chains, slings, shackles, and all the connecting hardware that bridges crane and load — are among the most safety-critical items in any lifting operation. Their correct selection, proper certification, regular inspection, and prompt retirement when defective are non-negotiable requirements that sit at the heart of LOLER compliance and, more fundamentally, of the basic duty of care that every crane operator owes to their team, their clients, and the public.
Invest in quality accessories from reputable, accredited suppliers. Maintain them properly, inspect them regularly, and remove them from service without hesitation when they show signs of damage or deterioration. The cost of doing so correctly is always modest compared to the consequences of failing to do so — consequences that, in a lifting environment, can be measured not just in financial terms but in human ones.
In rigging, as in all aspects of crane operations, there is no acceptable compromise on safety. The accessories your crane uses deserve the same standard of care as the crane itself — because, at the moment of a lift, they are equally important to its safe outcome.
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