Leaf Chains

What is leaf chain?

Leaf chain is a high-strength lifting and balancing chain made from layers of steel link plates held together by pins. Unlike roller chain, it has no rollers or bushes. Instead, its alternating sets of plates are laced together on solid pins, creating a very strong, compact chain designed to carry heavy tensile loads. Leaf chain does not engage with sprockets. It runs over plain pulleys, called sheaves, and is used to lift, lower, and balance loads rather than to transmit rotating power.

Leaf chain is best known for its use in forklift trucks, where it lifts the forks and load up the mast. It is also used in counterbalance systems, lifting equipment, machine tools, and anywhere a strong, reliable chain is needed to support heavy loads in tension.

A typical leaf chain has:

• Link plates - several steel plates side by side in each link, which carry the load
• Pins - solid pins that pass through the plates, joining the links together
• Plate lacing - the arrangement of plates in alternating links, which determines the chain’s strength
• End fittings - anchor bolts or clevises fitted to each end to attach the chain to the machine

Leaf chain is usually described by:

• Series - such as BL series for heavy-duty ANSI leaf chain, AL series for lighter ANSI leaf chain, or LH series for British and ISO leaf chain
• Pitch - the distance between the centres of adjacent pins, such as 3/4 inch or 1 inch
• Plate lacing - the number of plates in the alternating links, such as 2 × 3, 3 × 4, 4 × 6, or 6 × 6
• Length - often supplied in standard lengths, such as 10 feet, which can be cut to size
• Pin diameter and plate thickness - which affect strength and compatibility with end fittings

For example, BL634 leaf chain is a BL series chain with a 3/4 inch pitch and a 3 × 4 plate lacing, while BL823 has a 1 inch pitch and a 2 × 3 plate lacing. In BL references, the first number shows the pitch in eighths of an inch, so 6 means 6/8 or 3/4 inch, and 8 means 8/8 or 1 inch. The last two numbers show the plate lacing.

Key features:

• High tensile strength - multiple plates per link carry heavy lifting loads
• Compact design - high strength in a slim chain that runs over small sheaves
• Designed for lifting - built for tension, lifting, and counterbalancing rather than power transmission
• Runs over sheaves - works with plain pulleys instead of sprockets
• Range of lacings - more plates per link give higher strength for heavier loads
• Standard sizes - made to recognised ANSI and ISO dimensions for replacement and interchange

In simple terms, leaf chain is a strong, multi-plate chain designed to lift and balance heavy loads, such as raising the forks on a forklift truck.

Why is leaf chain essential?

Leaf chain is essential because lifting equipment depends on a chain that is strong, reliable, and predictable under heavy loads. Forklift masts, lifting platforms, and counterbalance systems rely on leaf chain to raise and hold loads safely. A worn or incorrect chain can stretch, crack, or fail, putting people and equipment at serious risk. Using the correct leaf chain, and inspecting and replacing it when needed, is vital for safe lifting.

Its main benefits are:

• High strength - multiple plates per link give excellent tensile strength
• Reliable lifting - designed specifically to support heavy loads in tension
• Compact - fits into tight spaces such as forklift masts
• Smooth operation - runs smoothly over sheaves for controlled lifting and lowering
• Durable - hardened steel components resist wear and fatigue
• Predictable wear - wear can be measured, allowing chains to be replaced before they become unsafe
• Standard sizes - makes replacement chain easy to source

Leaf chain is used across a wide range of industries and applications, including:

• Forklift trucks - lifting the forks and carriage on the mast
• Warehouse and material handling equipment - reach trucks, stackers, and order pickers
• Lifting platforms and hoists - raising and lowering platforms and loads
• Counterbalance systems - balancing heavy components on machine tools and equipment
• Vehicle lifts - lifting systems in garages and workshops
• Industrial machinery - presses, doors, and lifting mechanisms
• Construction equipment - telehandlers and lifting attachments
• Theatre and stage equipment - counterweight and lifting systems

The main types of leaf chain

Leaf chain is usually grouped by series, pitch, and plate lacing.

By series:

• BL series leaf chain - heavy-duty ANSI leaf chain with thicker plates, designed for higher loads and severe applications. Widely used on forklift trucks and heavy lifting equipment
• AL series leaf chain - lighter-duty ANSI leaf chain, using plates similar in size to ANSI roller chain, suited to lighter lifting and balancing applications
• LH series leaf chain - British and ISO leaf chain, commonly used on European lifting equipment and forklifts

Different series have different dimensions and strengths, so they should not be mixed or substituted without checking the equipment manufacturer’s specification.

By plate lacing:

• 2 × 2 and 2 × 3 lacing - fewer plates, for lighter loads
• 3 × 4 and 4 × 4 lacing - more plates, for medium to heavy loads
• 4 × 6 and 6 × 6 lacing - many plates per link, for very heavy loads

The more plates in each link, the higher the chain’s strength, but the chain also becomes wider and heavier.

By pitch:

• 5/8 inch pitch - for lighter lifting applications
• 3/4 inch pitch - common on forklifts and medium lifting equipment
• 1 inch pitch and above - for heavier lifting and larger equipment

Related products:

• Anchor bolts and clevises - end fittings that attach leaf chain to the mast or machine
• Sheaves - plain pulleys that the chain runs over
• Chain lubricants - penetrating oils that reach between the plates to reduce wear
• Chain wear gauges - used to measure chain stretch and check when replacement is needed

How to choose the right leaf chain?

Choosing the right leaf chain means matching it exactly to the equipment and load. For lifting equipment, always follow the equipment manufacturer’s specification. Work through these points in order:

• Equipment specification - check the manufacturer’s manual or parts list for the correct chain series, pitch, and lacing
• Series - match the chain series exactly, such as BL, AL, or LH
• Pitch - match the pitch to the existing chain and end fittings
• Plate lacing - match the lacing to the original chain, as it determines strength and width
• Load - make sure the chain’s breaking strength gives the safety margin required for the application
• End fittings - check the chain is compatible with the anchor bolts or clevises used on the equipment
• Sheave size - check the chain suits the diameter and width of the sheaves
• Length - order enough length to cut the chain to the exact number of pitches required
• Environment - consider moisture, dust, and corrosion, and plan for suitable lubrication
• Quality and brand - choose leaf chain from reputable manufacturers, made to recognised standards, for safety and reliability

How to fit leaf chain

Fitting leaf chain correctly is vital for safe lifting:

• Make the equipment safe - lower the load, secure the mast or lifting system, and isolate the equipment before starting work
• Check the specification - confirm the correct chain series, pitch, lacing, and length
• Inspect the sheaves and fittings - check sheaves, anchor bolts, and clevises for wear and damage, and replace them if needed
• Cut the chain to length - remove pins carefully to cut the chain to the exact number of pitches required
• Fit the end fittings - attach the anchor bolts or clevises securely, following the manufacturer’s instructions
• Fit the chain - route the chain over the sheaves and attach it to the anchor points
• Adjust the tension - set the chains so they are evenly tensioned, especially where two chains are used side by side
• Lubricate - apply a suitable penetrating chain oil so it reaches between the plates
• Test the equipment - check the equipment lifts and lowers smoothly, and arrange any required inspections before returning it to service

FAQ - All you need to know about leaf chain

What is leaf chain used for?

Leaf chain is used for lifting, lowering, and counterbalancing heavy loads. It is commonly found on forklift masts, lifting platforms, and counterbalance systems.

What is the difference between leaf chain and roller chain?

Roller chain has rollers that engage with sprocket teeth to transmit power. Leaf chain has no rollers, runs over plain sheaves, and is designed to carry high tensile loads for lifting.

What does BL634 mean?

BL634 is a BL series leaf chain. The 6 shows the pitch in eighths of an inch, so 6/8 or 3/4 inch. The 34 shows a 3 × 4 plate lacing.

What does plate lacing mean?

Plate lacing describes the number of plates in the alternating links of the chain, such as 2 × 3 or 4 × 6. More plates give higher strength but make the chain wider.

Can I use a different series or lacing?

Not without checking the equipment manufacturer’s specification. Different series and lacings have different dimensions and strengths, and the wrong chain may not fit the sheaves and end fittings or carry the load safely.

Can leaf chain be joined or repaired?

Leaf chain should not be joined with connecting links, repaired, or welded. If it is damaged or worn, replace it with a complete new length of the correct chain.

Should leaf chains be replaced in pairs?

Yes. Where two chains are used together, such as on a forklift mast, they should be replaced as a pair so they share the load evenly.

When should leaf chain be replaced?

Replace leaf chain when it reaches the manufacturer’s wear limit, often around 2% to 3% elongation, or if it shows cracked plates, protruding or turned pins, tight joints, corrosion, or other damage.

How do I check leaf chain wear?

Measure a set length of chain with a chain wear gauge or tape measure and compare it with the original length. Also inspect it for cracked plates, loose or rotating pins, stiff joints, and corrosion.

How should leaf chain be lubricated?

Use a penetrating chain oil that reaches between the plates and pins. Lubricate regularly, especially in dusty or damp environments, as dry chains wear much faster.

Does leaf chain need to be inspected?

Yes. Leaf chain on lifting equipment should be inspected regularly, and lifting equipment is usually subject to thorough examination requirements, such as LOLER in the UK. Follow the equipment manufacturer’s inspection schedule.