Do Chainsaw Chains Stretch? Tips from a Professional

Sharp and tight chainsaw chains provide an efficient and much smoother cutting performance. Due to their operational wear and tear, chains can elongate over time. They can become loose and their cutting performance can get compromised. If you’ve faced this condition with your chain before, don’t worry as I discuss in the blog post the causes behind this and possible solutions.

Do chainsaw chains stretch?

Chainsaw chains will stretch when they are used. Chains elongate by a considerable margin after their first use. Afterward, they gradually elongate with time due to wear and tear. Adverse operating conditions accelerate chain stretching behavior. Keeping chains well maintained by ensuring lubrication, timely sharpening, and protection against harsh conditions is the key to their longevity.

In this blog post, I will explain in more detail how a chainsaw chain stretches. Why this can happen really quickly, and some solutions.

Do Chainsaw Chains Stretch over Time?

Chainsaw chains stretch over time to mechanical wear and thermal expansion. Timely chain maintenance and lubrication effectively reduce the degree of elongation over time. 

Technically, chainsaw chains don’t stretch, rather the chain loop gets longer after repeated use. This is because frequent use will slowly remove material from the chain links and bushings and increase the link clearance. As a result, your chain loop will become longer.

How much will a Chainsaw Chain Stretch?

Chainsaw chains stretch considerably after their first run, with about 1/100 of an inch per link. A longer chain with 75 links stretches around 0.75 inch. A shorter chain will still stretch almost half an inch. After this initial stretch, they continue to elongate gradually due to fatigue.

Chain elongation can be of three main types.

1. Initial Chain Stretching:

All new chainsaw chains stretch by a certain amount after their very first use. The rivets that connect the chain links all have a specific amount of clearance (about 1/100 of an inch) in each direction. As you run a chain in one direction, all the rivets get pulled towards one side of the clearance. Hence, if your loop has 50 chain links, then it would have stretched by about half an inch after first use.

Most new users get concerned when they see their chain getting stretched after first use. However, the initial chain stretch is usually unavoidable, and it happens at the very first run of a brand-new chain. Hence, after this, you may need to adjust your chain tension to cater to the stretch.

2. Prolonged Chain Wear:

After the initial elongation, chains continue to wear as they are subjected to use regularly. Conditions such as dirt exposure, blunt teeth, hard surfaces, tough cutting angles, and debris all contribute to the wear and tear of the chain and its mechanical linkages. Probably the biggest contributor to chain wear is insufficient lubrication.

All these factors result in gradual material removal from the chain links (wear and tear), thereby increasing its length by a small amount over time. Although you can’t eliminate this gradual stretch, however, it can be slowed down by ensuring that the chain is maintained properly.

3. Thermal Expansion:

The third type of chain elongation is due to thermal expansion. When a chainsaw is run at full throttle, the chain gets heated up significantly. This causes its links to thermally expand, and it sits loosely on the guide bar. However, as it cools down, the loop returns to its original dimensions.

Hence, if your chain gets loose when hot, wait for it to cool down so that it thermally contracts. Always remember not to use the chain tension adjuster to tighten a thermally expanded chain. On contraction, the chain could cause irreversible damage to the guide bar and sprocket.

Why does a Chain Stretch?

The chainsaw chain doesn’t technically stretch, rather it elongates due to wear as it’s operated continuously. The prolonged use removes material from the bushings connecting chain links, thereby increasing the chain’s length to some extent.

Chainsaw chains consist of individual links and cutter teeth held together through pins and rivets. In modern chainsaws, the engine RPMs range from 5000 up to 15000. At such rotational velocities, the chain experiences immense sliding friction as it slides in the guide bar rails. The high fatigue stresses coupled with heating effects result in very small and gradual material removal from the chain-link bushings over time. Due to this continuous wear rate, chains continue to elongate as time passes.

How do I know if my Chain is Tight Enough?

To determine if the chain is tight enough, you can either ‘pull’ the chain from the guide bar’s groove until the drive links are visible. Or you can ‘pull and release’ the chain to see if the drive links snap back into the groove.

• Pull Test: Use your fingers to pull out a drive link as far as you can from its position in the bar’s groove. As a rule of thumb, the link should only be pulled out by about half an inch. If it comes out more than that, the chain is loose and its tension should be adjusted.
• Snap Test: Alternatively, you can pull out the drive link from its position and see how far it can go. After that, release the drive link. If it snaps back to its place instantly, that’s a sign of appropriate chain tension. Whereas, if it just sags instant of snapping, your chain is not tight enough.

Both these ways can help you get the hang of your chain’s tightness.

Why does my chainsaw chain stretch so fast?

A chainsaw chain working in a harsh working environment wears out at a rapid rate. Always ensure that the oiler pump is working and supplying enough lubricant to the chain. Furthermore, you should always keep the chain sharpened and clean its groove from debris deposits.

If you notice that your chain is elongating at an unusually high rate, there could be three main reasons behind this:

1. Harsh Operating Conditions:

Cutting dusty wood is a huge contributor to the chain dullness and wear rate. Always ensure that you wipe off the dust before sawing wooden logs. Furthermore, cutting wood with a blunt chain exerts more stress on the drive link and accelerates their wear rate. Hence, if your chain is stretching so fast, keep an eye on the operating conditions it is subjected to.

2. Inadequate Lubrication:

From experience, I can tell you that the number one reason behind chain dullness is inadequate lubrication. I’ve seen cases where users kept using their saws with faulty oiler pumps, thus causing the chain to stretch due to fatigue. Always check that your oiler pump is working correctly and the oil lines are free from debris. If you use a longer guide bar (such as 20-inches), your oiler setting needs to be at maximum. It is better to consult your device’s manual to find the recommended oil setting for the chain.

3. Worn-out Sprocket:

Another problem you can have is a worn-out sprocket. This accelerates the fatigue behavior of your chain more than you expect. Sprockets need to be replaced after every two chains, as per most user manuals. To change your sprocket, unscrew the clutch drum and use a wrench to remove the sprocket.

Why won’t my Chainsaw Chain Tighten?

If your chain doesn’t tighten by the tension adjuster, try employing the proper technique by loosening the nuts holding the guide bar. If the problem persists, adjust the length of the loop by removing a few links from the chain.

Once you notice your chainsaw chain hanging off loose, it is advisable to tighten it using the automatic tension adjuster. Using a chainsaw with a loose chain has its risks and it should be strictly avoided under all circumstances.

1. Chain Tightening Procedure:

Adjusting the chain’s tension on the guide bar is fairly simple and can be performed in just a couple of steps.

• Loosen the bar’s mounting bolts: Before you tighten the chain, loosen the two mounting bolts that secure the guide bar. You would need an appropriately sized socket wrench for this job. Make sure you only loosen the nuts and don’t remove them entirely.
• Tighten the adjustment screw: The adjustment screw is located separately from the mounting bolts. Use a suitable socket wrench to turn the screw in a clockwise direction. This would tighten the chain. Keep turning the screw until the chain is tight enough to snap back if pulled from its position. Avoid fully tightening the chain, as this could result in damage.

2. Removing Chain Links:

If tightening the adjustment screw still doesn’t tighten the chain enough, your chain’s length needs to be shortened. To do this, you need to locate the master link in the chain. The master link is a special link that can be used to easily open and remove certain links from the chain loop. Look out for the master link in your chain, which is different in appearance from the ordinary links.

Using a flat head screwdriver, open the master link to break the loop. Remove the link located next to the master link using pliers. Keep removing links as per the need to achieve your chain’s desired fit. Once done, reattach the master link and test the chain’s tension again.

How Long should a Chain Last on a Chainsaw?

The exact lifetime of a chainsaw varies depending on the quality and duration of use. Most chainsaw chains can last as much as up to 4 years if maintained properly. If treated harshly, a chain may need a replacement after a year.

Most manufacturers rate their chainsaw chains to last up to 4-5 years. Chains that are well maintained can last as long as that period. Let’s have a look at what constitutes a well-maintained chain:

• Lubrication: Chain maintenance includes ensuring its timely lubrication. Chain lubrication reduces friction between metal surfaces and guarantees a smoother operation.
• Sharpening: In addition, chains should be sharpened after 5-7 hours of use. Using a sharpened chain results in seamless cutting and reduces stress on the overall chain links.
• Avoid Harsh Use: Avoid using your chain in adverse operating conditions as this could shorten their life. These conditions include exposure to dirt, rough surfaces like rocks, hard objects such as nails, etc.