Your Guide to Buying a Chain for a Chainsaw

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Your Guide to Buying a Chain for a Chainsaw

Chainsaws are used to prune foliage, fell trees, and cut firewood. They can also be used for chainsaw art and, with the addition of specialist chains, cutting concrete. Chainsaws can be powered by compressed air, electricity, rechargeable batteries or – more usually – a two stroke petrol engine. No matter the power source, all chainsaws have the same basic construction.


A chainsaw is powered either by an electric motor, a rechargeable battery, or a petrol powered engine.

Drive mechanism

A clutch which links the chain and engine, and a toothed wheel (or sprocket) that turns the chain, makes up the mechanism that drives the chain.


Also known as a guide bar, this is a notched, elongated, flat panel that guides the chain.


A toothed, sectional, cutting chain whose links are connected by rivets to allow a sinuous movement.

Chainsaws are available in a variety of sizes which are categorised by length. This length is calculated by measuring the tip of the cutting edge to the entry point of the chain into the housing. Each chainsaw size is appropriate to a certain task or regularity of usage.

Light use

Foliage, low hanging branches, small trees, and irregular tasks.

Medium use

Logs, small trees, and frequent use.

Heavy use

Regular use, heavy duty tasks, and professional operation.

Bar length is critical to the efficiency and safety of chainsaw operation. If the chain is too long, the chainsaw may kickback towards the operator, causing severe injury; if the chain is too short, the chainsaw could ‘stick’ in the wood, pinch, and then kickback, again potentially causing severe injury. The chain must correspond to the bar length to ensure accurate and safe usage, and there are three basic specifications to allow an effective calculation of size requirement.


Gauge refers to the thickness of the links and is calculated by the size of the bar. The chain must match the bar - too large will slip and too small will not fit.


Pitch can vary and is calculated by measuring the distance between three rivets and dividing it by two. The pitch and sprocket must be compatible or the chain will slip and impede efficiency.


The length is defined by the number of links. The bar, chain, and sprocket must always be of compatible size to ensure a safe and productive cutting action.

How to Sharpen a Blunt Chain

Damaged chains can be sharpened in an eight step process in order to extend the life span and effectiveness of the cutting edges. Nevertheless, over-sharpening is inadvisable as the individual teeth must be no shorter than ¼ inch or there will be a risk of breaking during normal chainsaw use.

Determine the size or gauge of the chain.

There are a broad range of files available for the specific purpose of chainsaw blade sharpening. An incorrect file size will damage the chain and render it useless.

Clean the chain thoroughly.

Remove old chain oil and dirt from the chain but be aware that excessive application of cleaning agents may damage the housing or other engine parts. In order to lessen this risk of damage, ensure that all fluids are minimally applied.

Use a vice for stability.

By leaving the chain on the bar and clamping the bar securely, there is room for the chain to rotate naturally whilst remaining safely fixed.

Mark the first tooth sharpened.

All teeth should be filed to the same length so that they each cut the same amount of wood as the chain rotates. Marking the first tooth ensures that teeth are not over-filed or foreshortened.

Hold the file at the same angle as the tooth.

It is essential to match the angle of the original machining. Some manufacturers have ‘witness markers’ to visually aid filing.

Use a twisting movement.

By using a minimal twisting motion, the metal filings will be ejected. Generally, using the file from the short side towards the long point should produce a smoother cutting surface.

Always work the tooth using the same angle.

As filing progresses, spin the chain around the bar to ensure that all teeth are filed on the top side of the bar.

Reverse the saw to finish the job.

To ensure that all teeth are filed equally, reverse the bar to allow a continuation of movement, and ensure that all teeth are filed to the same length.

How to Replace a Chain

If a chain is too damaged to sharpen, ready-joined lengths can be purchased. Produced to fit specific bar sizes, these chains are relatively easy to replace:

Remove the bar side panel.

The side plate on most chainsaws will most likely be held on by two nuts. Unscrew these nuts and remove the panel to access the chain. Ensure that the chainsaw brake is disengaged before removing the panel as a locked brake will make it very difficult to reassemble the housing.

Release the chain tension.

The chain should be easy to remove when the tension has been released. Lift the links off the guide bar and slip the chain over and around the clutch.

Loosen the tensioning screw.

Located on the inside of the guide bar, loosening the tensioning screw will make installing the new chain easier.

Thread the chain onto the bar, and then align the bar.

When the chain is fitted along the bar, pull on the nose of the bar to add tension. Whilst doing this, ensure that it is settled onto the adjustment pin.

Replace the side panel.

Do not tighten the nuts completely as the bar must be able to move a little in order to allow the chain to be properly tightened.

Adjust the tension.

Using the tension screw, tighten the chain to the appropriate level.

Finish tightening the side panel nuts.

With this final action, the chain replacement is complete.

For heavy use and the associated possibility of a more regular chain replacement, perhaps purchasing a bulk chain amount would be more appropriate. This chain is also available in a range of sizes, stored on spools or reels, but it must be cut to the desired length before being joined by inserting rivet pins.

How to Remove a Link

A chain can also become stretched and, with the correct tools, removing a link to shorten the chain can render it good for use again:

Place the chain on a flat surface.

Turn the handle on the chain tool until the arm retracts then fit the tool over the link to be removed and line up the arm with the pin.

Remove the pin.

Turn the handle until the arm forces the pin from the link, then repeat on the opposite side. Pull the link from the chain.

Reconnect the chain.

Put the pin in the hole, put the tool over the link and turn the handle until the pin is forced back into the hole.

How to Buy Chainsaw Chains on eBay

To buy chainsaw chains, first go to the eBay homepage, opening the All Categories tab, then click on the link for Home & Garden. Next choose Garden, followed by Power Tools & Equipment from the drop down menu. Then click on Chainsaw Parts & Accessories in the left hand menu and choose Chain in the filter options. Available item listings will then be available for consideration. Alternatively, use the search bar at the top of any eBay page. For example, to find a pack of 20 inch long chainsaw chains, simply type in “chainsaw chain 20”.


A chainsaw is used to prune foliage, fell trees, and cut firewood and can be powered by electricity, rechargeable batteries, or, more commonly, a petrol engine. Cutting chains must directly correlate to the guide bar which can be calculated by measuring gauge, pitch, and length. Stretched chains can be shortened by removing a chain link and worn chains can be replaced with either ready-joined lengths or by cutting a bulk-purchased chain to the desired length.

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