What Is a Fleyer Chain (Leaf Chain)? Coding, Sizing and Applications

What Is a Fleyer Chain (Leaf Chain)?

Unlike common roller chains, a fleyer chain contains no rollers or bushings; it is a type of chain made up solely of stacked side plates (leaves) and the pins that connect them. In Turkish, it is known as a leaf chain, while in the industry it is often called a fleyer chain or or leaf chain .

Thanks to this structure, a fleyer chain devotes a far greater share of its cross-sectional area to load-bearing than a roller chain of the same outer size. The result: high tensile strength. On the other hand, it is not designed to run over a sprocket; it transmits linear motion by passing over a pulley.

For our product group, flyer chains page, or for an application-specific assessment, Ankara chain company you can contact our technical team.

Difference Between Fleyer Chain and Roller Chain

This difference matters: a fleyer chain does not fit on a sprocket, and a roller chain cannot take the place of a fleyer chain in lifting applications. The two types are not alternatives to one another, but solutions for different tasks.

Plate Arrangement and Coding System

The load-carrying capacity of a leaf chain is determined by how many plates are arranged side by side on each pin. This arrangement number of inner plates × number of outer plates is expressed in this format: 2×2, 3×4, 4×4, 4×6, 6×6, and so on.

Two coding families are used in the industry:

• LH series (ISO 4347 / DIN 8152):such as LH0822, LH1234, LH1644. The first two digits of the code indicate the pitch group, while the last two digits indicate the plate arrangement.
• BL series (ANSI B29.8):such as BL422, BL634, BL846. The first digit indicates the pitch group, while the next two digits indicate the plate arrangement.

Pitch Sizes Corresponding to Code Groups

Example reading: LH1234 refers to a leaf chain with a 19.05 mm pitch and a 3×4 plate arrangement.

Since breaking load values vary depending on both pitch and plate arrangement, in critical lifting applications you should request the relevant catalogue and test values for the chain from your supplier. For the measurement method, you can refer to our chain sprocket dimensions page.

Where Is Leaf Chain Used?

• Forklift and stacker masts: This is the most common application. Raising and lowering the forks is achieved with the leaf chain. For information specific to this application, see our forklift chain page.
• Balancing (counterweight) systems: Used to carry the counterweight in lifts and hoisting mechanisms.
• Presses and injection moulding machines: For positioning moulds and moving platens.
• Cranes and lifting equipment: For transmitting linear lifting motion.
• Automation and positioning mechanisms: On axes requiring precise linear motion under high load.

The common feature of lifting applications is that, in the event of failure, the outcome is not just a production loss but a safety risk. For this reason, the safety factor used when selecting a leaf chain is kept noticeably higher than for power transmission chains.

What to Consider When Choosing a Leaf Chain

1. Determine the actual working load and safety factor. In lifting applications, the chain's minimum breaking load must be well above the working load. The factor applied is determined by the standard the machine is subject to and the risk assessment.
2. Match the plate arrangement to the load. Choosing a 3×4 or 4×4 arrangement instead of 2×2 at the same pitch is the most practical way to increase load-carrying capacity without enlarging the installation dimensions.
3. Check the pulley diameter. If the diameter of the pulley the chain runs over falls below the manufacturer's specified minimum, fatigue in the plates accelerates.
4. Don't forget the connecting element. Leaf chains are usually attached to the system with clevis-head connecting pins. Even if the chain itself is correctly selected, if the connecting element is weak, the system's load-carrying capacity is limited by that element.
5. Assess the environmental conditions. In damp or chemically exposed environments, corrosion increases friction between the plates, causing the chain to stiffen. For protection options, see our corrosion and rust prevention article.

Maintenance and Replacement Time

In leaf chains, wear occurs at the contact surface between the pin and the plate hole, and shows itself as elongation of the chain. The points to check are:

• Elongation measurement: With the chain held taut, the length of a specific number of links is measured and compared with the new-chain measurement. When the elongation exceeds the limit specified by the manufacturer, the chain is replaced.
• Plate cracking: This is seen especially around the pin holes and is the clearest sign that the chain has reached the end of its remaining service life.
• Stiff (non-rotating) links: If the chain does not bend smoothly as it passes over the roller, there is corrosion or a lack of lubrication in that area.
• Pin rotation or slippage: Lateral displacement of the pin requires immediate replacement.
• Lubrication: A lubricant capable of penetrating between the plates should be used. Grease that remains on the surface without penetrating inward does not extend the chain's service life.

Partial repair of leaf chains (removing or adding links) is not recommended for lifting applications; the chain is renewed as a whole.

Frequently Asked Questions

Can a leaf chain be used with a sprocket?

No. Since a leaf chain has no rollers, it is not designed to run on a sprocket. It transmits linear motion by passing over a roller or pulley. If sprocket drive is required, transmission chain should be used.

How do I determine the code of my existing chain?

Measure the pitch (the distance between the centres of two consecutive pins) and find the code group from the table above. Then determine the arrangement by counting the number of inner and outer plates on the pin. These two pieces of information are usually enough to identify the correct equivalent; to be certain, it is recommended that you also provide the plate height and thickness.

What should I do if a higher load capacity is required at the same pitch?

The plate arrangement is increased. For example, switching from a 2×2 to a 3×4 arrangement raises the load capacity without changing the pitch — and therefore the roller dimensions. This is the most practical solution in systems with limited installation space.

What is the replacement interval for a forklift chain?

Instead of a fixed period, a measurement-based criterion is used: the chain is replaced when its elongation exceeds the limit specified by the manufacturer, or when cracks are seen in the plates. Operating intensity and environmental conditions significantly alter this period; periodic measurement should be included in the maintenance plan.

Conclusion

Thanks to its rollerless construction, a leaf chain offers a higher tensile strength than a roller chain of the same size, and it is the standard solution for lifting, balancing and positioning applications. The correct choice is made by evaluating the pitch, plate arrangement, roller diameter and connecting element together.

Please send us the dimensions and working load of your current chain so we can determine the right flyer chain for your forklift mast, press or lifting system. You can create a quote request, for all groups our products you can review.

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