Why do roller chains elongate | Chain Hub

Why do roller chains elongate?


Roller chains are a crucial component of a wide variety of machinery, ranging from heavy machinery and industrial equipment to agricultural machinery and other forms of equipment. They are constructed in such a way that power can be efficiently transferred from one shaft to another while still preserving the correct speed ratios.

Roller chains, on the other hand, are susceptible to wear and elongation over time, which can lead to a decrease in efficiency, increased expenses associated with maintenance, and even the complete breakdown of the system. So with this in mind, what are the typical factors that lead to roller chain wear and elongation, as well as the potential remedies to these problems?

What exactly is meant by “Roller Chain Wear”?

As two metal surfaces rub against each other during operation, wear takes place. This causes material to be worn away from the surfaces that are in touch with each other. The process of wear is affected by a variety of parameters, including the speed, loading, lubrication, alignment, and the circumstances of the surrounding environment. The bushings and pins, which are located at the main bearing point where the chain articulates, are the areas of the chain that wear out the most frequently.

Elongation of Roller Chain: What Does That Mean?

Elongation of a roller chain occurs when the chain gradually grows longer over time as a result of wear on the pins and bushings. When the material of the chain wears away, there is more space between the pin and the bushing. This causes the chain to get longer since there is more space than necessary between the pin and the bushing. This results in the chain riding higher on the sprocket teeth, which decreases the chain’s efficiency and increases the likelihood that it will skip teeth or leap off the sprockets. Despite the fact that the chain does not actually expand in this way, this phenomenon is usually referred to as chain stretch. When a chain has stretched by 3% from its initial length, it is generally recommended that the chain be replaced.

What are the most common factors contributing to the wear and elongation of roller chains?

Wear and elongation of roller chains can be caused by a number of different sources. The following are some of the most frequent:

Insufficient Lubrication Roller chains need to have the appropriate amount of lubrication applied to them in order to lessen the amount of friction and wear that occurs between the chain components. It’s possible that inadequate or poor lubrication might cause the chain to wear out quickly, which would then lead to premature elongation. (RotaLube reference?)

Quality of Chain Construction: The quality of the components used in the chain’s construction is a significant factor. The bushing is the most important component, and it can either be split or solid depending on your preference.

Overloading: When a chain is subjected to loads that are too great for its intended capacity, the chain may become stretched out and elongated over time as a result of the excessive stress. This happens a lot in industrial applications because large loads and high-speed operations can quickly induce wear and elongation of the material. The maximum recommended working loads for any given chain size should under no circumstances be exceeded by loads.

Contamination: The chain may be susceptible to contamination from dirt, dust, and other forms of abrasive particles, which can lead to increased friction and wear. Contaminants can potentially promote corrosion of the metal components, which can further accelerate wear and elongation over time.

Corrosion: Roller chains that are used in locations that are known to be corrosive may undergo accelerated wear due to the corrosive action of chemicals or moisture on the metal surfaces. Corrosion can be caused by both of these factors.

Misalignment: If the sprockets are not properly aligned, the chain will be subjected to higher stress, which can lead to rapid wear and elongation of the chain. This can occur when the sprockets are not properly aligned. Incorrect installation, worn sprockets, or excessive axial or radial loading can all contribute to misalignment of mechanical components.

Metal fatigue: Failure due to metal fatigue can be caused by the loading cycle being repeatedly applied to the chain.

High temperatures: Working at temperatures that are too high for the chain’s specification causes problems. The metal portions of the chain need to have the potential to expand and contract when the chain is operated at temperatures that are too high. This can lead to increased wear and elongation of the chain.

What are the different ways these problems could be solved?

Roller chain elongation and wear are common problems, but thankfully there are multiple solutions available to alleviate each of these issues. The following are examples of some of the most useful solutions:

Lubrication done right: Using the appropriate lubricant and making sure it is applied on a consistent basis will assist lessen the amount of friction that occurs and lengthen the chain’s lifespan. RotaLube automatic chain lubrication systems apply the correct amount of lubrication to the critical parts of the chain resulting saving of energy, time and oil. (Link here)

Cleaning: Routine cleaning of the chain can assist in the removal of pollutants that may lead to the chain wearing out and becoming longer.

Correct alignment: Making sure that the sprockets are correctly aligned will help to lessen the amount of stress that is placed on the chain, which in turn can lengthen the chain’s lifespan.

Management of the load: To avoid accelerated wear and elongation of the chain, it is important not to overload the chain and to operate it within the recommended load range.

Temperature management: It is important to keep an eye on the working temperature of the chain and make sure that it stays within the recommended range in order to prevent thermal expansion and contraction, both of which can cause the chain to wear out and become longer. Wear can be reduced by using a lubricant that has been specifically designed for use at high temperatures.

Inspection at regular intervals: Carrying out inspections of the chain at regular intervals to look for signs of wear and elongation can assist in the early detection of problems and the prevention of problems with a greater degree of severity.

Chains that solve the problems

In addition to a wide variety of speciality roller chains, corrosive and high temperature resistant roller chains are also available. The following are some examples:

Stainless Steel

The roller chains made of stainless steel are an excellent choice for use in environments that are both highly corrosive and extremely hot.

Sealed O-Ring Roller

O-ring roller chain is an excellent solution for chain drives in situations where it is difficult to re-lubricate the chain. Lubricating the chain on a regular basis is something is recommended to be done in order to prevent the o-ring from drying out and cracking.

Roller Chain That Doesn’t Need Greasing

There is also the option of using a self-lubricating roller chain in places where lubrication is not necessary, such as in clean settings in food production.


Wear and elongation of roller chains are common issues that can have a major influence on the functioning of machinery and equipment. However, if steps are taken to address the underlying causes of these issues, such as proper lubrication, cleaning, alignment, load management, temperature management, and regular inspection, it is possible to extend the life of the chain and maintain optimal system performance.

Equipment owners can avoid downtime caused by roller chain failure, reduce maintenance costs, and boost efficiency all by applying the solutions provided in this article. We’re happy to help so please contact us.

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