How to Measure Chainsaw Bar and Chain?

Need new chainsaw bar and chain?

Aaron Barnett of BangingToolbox suggests: You may not know the importance of getting the right chainsaw bar and chain size until you get into a kickback accident from not having the correct fitting chain or bar length to keep you further away from the cut.

Long bars are safer to use for ground cutting, while shorter bars are safer for use at heights. 

Whether your chainsaw bar or the chain is worn, broken, or cracked, you need to replace it to find parts that fit each other and are the correct sizes for each other.

The wrong size of the bar or chain could end up tracking improperly, which not only be unsafe or not possible to use.

But potential kickbacks and injuries are more dangerous if you are using the wrong size bar for the job you are doing.

Measuring these two parts of the chainsaw can be confusing. For the most part, you need to measure the chainsaw bar in inches, the chainsaw pitch in millimeters, and the gauge in thousands of an inch.

Other confusing terms are the chainsaw bar length and the chainsaw true bar length. And how you compare measurements – to the advertised chainsaw length. This adds up to the confusion before you can purchase your replacement.

All these measurements are crucial when purchasing a replacement for your bar and chain on your cordless chainsaw.

To remove all this confusion, we made an easy-to-follow guide on measuring the chainsaw bar and chain below.

A few measurement terms to know

You do not simply go to a shop or online marketplace without knowing the needed information. You need to refer to crucial measurements when buying a chainsaw bar and chain.

Chainsaw Bar Length

The chainsaw bar length, also referred to as the cutting length, is the distance from the tip of the end of the bar to the point it meets the chainsaw body.

This measurement will give you an idea of how much you can cut through trees.

For example, a shorter cutting length can cut smaller trees. A smaller cutting length will not work if you have to cut larger trees. 

When cutting firewood on the ground, a longer bar reduces the need to bend over (hurting your back) and distances yourself more from the cut in case of a kickback.

Chainsaw True Bar Length

The true bar length of a chainsaw is its full measurement from end to end.

While this measurement is not commonly used, this is the exact measurement of the bar.

However, manufacturers sell chainsaw bar lengths in even-numbered measurements.

Groove Gauge

The chainsaw chain’s groove gauge is the thickness of its drive link tips traveling within the chainsaw bar groove.

This measurement will help you determine how much the chain can cut through the wood.

Pitch

The pitch is the distance between the chainsaw chain’s link [1]. This part engages with the sprocket to turn the chain. Sizes go 1/4”, .325”, or 3/8”.

Drive Links

Chainsaw drive links are the teeth that fit inside the chainsaw’s bar groover. You need the link count to determine the pitch, gauge, and chainsaw length.

How do you measure the chainsaw bar?

Step 1. Turn off the chainsaw and disengage the ignition switch or power source.

Before turning the chainsaw off, ensure that the engine stops completely if you just finished working.

With the saw pointing away from you and to the ground, switch the ignition off. This is an important step, especially if you are working with a gas chainsaw.

Let the engine cool for 15 minutes. Turn off your power supply.

The chain brake is a safety feature on chainsaws. Disengage the chainsaw engine brake by pressing the front handle and pulling the chain brake lever.

Step 2. Measure the cutting length.

Lay the chainsaw flat and secure or clamped inside a vise grip on your workbench.

Wear gloves to avoid cutting your fingers. Use a tape measure to know the cutting length of the bar. 

From the chainsaw bar tip, measure all the exposed parts of the chainsaw bar to the body.

Round it up to the next even number. For example, if it measures 18-6/8 inches, that would be 20 inches. That is your cutting length.

Step 3. Remove the chain from the bar.

Find those two nuts on the right portion of your chainsaw.

Unscrew these nuts holding the clutch cover with a wrench. Pull off the bar completely. Here’s how you can untangle chainsaw chains.

Step 4. Measure the true bar length.

Using your tape measure, measure the true bar length from end to end.

How do you measure the chainsaw chain?

Step 1. Turn the chainsaw off and disengage.

If you have been working on the chainsaw, allow it to stop completely before turning the ignition off.

Make sure the chainsaw does not point toward you.

Turn the ignition off and let it cool for fifteen minutes. Turn off the power supply.

Step 2.  Remove the chain from the bar.

Makes sure to wear gloves for this process. Position the chainsaw on a secure flat surface. 

Locate the nuts holding the clutch and unscrew it with a socket wrench. Remove the entire bar and unloop the chain.

Step 3. Measure the chainsaw pitch.

To obtain the chainsaw pitch, measure the distance between the chain links using three rivets.

Start from the exact center of one rivet passing through the second one and ending at the center of the third rivet.

After getting the measurement, divide this number by two. If it measures 6/8 of an inch, that would be 3/8 of an inch.

Step 4. Take the size of the chainsaw bar groove gauge.

There are two ways to take the size of the groove gauge. You can use a Vernier caliper or use the coin method.

If you have a Vernier caliper, place your chain’s drive links in between the jaws of the caliper.

Slide the jaws until closed to grip the link tightly. Note the measurement displayed on the caliper.

If you do not have a Vernier caliper, use the coin method. Get a penny, a dime, and a quarter coin.

Whichever fits snugly on the chainsaw bar’s groove is the measurement.

A dime measures 0.050 of an inch. A penny measures 0.058 of an inch. And a quarter coin measures 0.063 of an inch.

Step 5. Count the drive links.

The drive links are the pointed tips that fit into the bar groover.

Count them to measure the length of your chain.

Simply mark one drive link, and start counting from there until you reach the drive link before it.

Now you have the measurements you need the most!

Now you have all the information about your chainsaw bar length and chain length, take note of all the measurements and write them on your shed wall so that you don’t have to do it again.

You now have the cutting length, true bar length, pitch, gauge, and drive link count.

These measurements are enough to guide you on your chainsaw bar and chain replacement to help you with your tree-cutting project.

Always have a backup chain ready to go in case it breaks on a job.