Chainsaw Chains and Chainsaw Bars Sizing

Chainsaws are powerful tools that can be used for a variety of jobs, from cutting large trees and logs to pruning shrubs and harvesting firewood. Keeping chainsaw chains sharp help with performance and safety.

When choosing a replacement chainsaw chain or bar, first check your chainsaw’s manual to see if sizing information is provided. If not, you need to take the chain measurement and bar measurement. Chain size varies by manufacturer so even if you choose a new chain in the same length as your old one, it may not fit your specific chainsaw.

Chain sizes are measured by pitch, gauge, and the number of drive links. If you don’t have access to your chainsaw’s manual, you may be able to find its chain size stamped on the chainsaw bar. This information is typically found near the part of the bar closest to the body of the saw. If you can’t find this information on the chainsaw bar, you can take your own measurements.

Pitch is the distance between the chain’s links. It’s usually indicated by a fraction like 3/8-in or ¼-in. To measure the pitch, use a ruler or tape measure to check the distance between the three consecutive rivets on the chain. Rivets are the round metal pieces that secure the chain links. Then, divide this number by two.

Gauge refers to the thickness of drive links. It’s also indicated by inches but in decimal form, such as .050-in. or .058-in. To measure the gauge, place a multi-purpose gauge or caliper on the groove where the chain fits into the bar and record that measurement.

Drive links are the pointed metal pieces on the chain’s interior. The number of links on the chain are whole numbers and are often labeled with the letters “DL”. To measure the number of drive links simply count the total number of links on the chain. Mark the link where you start counting to make it clear where to stop.

Another chainsaw part that may need replacing is the chainsaw bar.

To measure a chainsaw bar, place the chainsaw on a flat surface, like a work bench, and measure from the outward facing tip to the base of the chainsaw, the point closest to the body of the chainsaw.

Once you have this measurement, round that number to the closest even number. For example, if you measure 17 ½, round up to 18. This measurement, referred to as the “called length” or “cutting length,” is the useable length of the bar.

To safely sharpen a chainsaw’s blade, always check the chain manufacturer’s instructions first. Some chains require a specific method and shouldn’t be sharpened manually. In this case, you’ll want to have the chain and depth gauges of your saw sharpened by a professional.

If you can sharpen the chain manually, purchase a sharpening kit which has all the tools you need, including a round file, flat file, file guide and depth gauge. Before attempting to sharpen a chainsaw blade, always remember to wear work gloves to protect your hands. Just because a blade is dull, doesn't mean it can’t cause damage. You’ll also want to ensure the power is off and the chainsaw is disconnected from its power source.

For in-depth instructions on how to sharpen a chainsaw blade, check out our guide on How to Start, Use and Maintain a gas chainsaw. Or, check instructions on how to maintain a battery-powered chainsaw. You can also review our guide on Chainsaw Safety, which will help you understand common safety features of chainsaws including the stop switch, chain catcher, clutch cover and more. Chainsaws are extremely powerful tools and should be used with extra precaution.