A chainsaw with a well-maintained chain enables you to work for long hours without getting fatigued. The chain can cut deep into the wood and do so efficiently. A dull chain will quickly tire you out and add unnecessary strain on your chainsaw. Not using a chainsaw file size chart may lead to the saw to produce too much sawdust that clogs the chainsaw’s air filter. A dull chain also increases the chances of a kickback occurring, which can lead to accidents. In this guide, you will learn how to choose the right file size for your chain and the different types of files and gauges, to get a nice sharp chain.

What is the Size Chainsaw File Determinant?

A particular file can only sharpen a particular chain. The manual that comes with your chainsaw will have the instructions that will help you to choose the right file and gauge. However, if you do not have your manual, this guide will come in handy as well. To get a deeper understanding of why each chainsaw needs a special file, you need to have a basic understanding of the cutting component of the chain.

The part of the chain that does the cutting is called the cutter. It is the one that must be filed to maintain its sharpness. Once the cutter has been worn down to a certain depth, it must be replaced. Chains have markers that can help you establish if it is time to replace it. The three main types of cutter teeth are the chipper, chisel, and semi-chisel. A chain has both right-hand and left-hand cutters. The two of them ensure that the saw cuts evenly through the wood.

chainsaw tooth types

Round or Chipper Tooth

This chipper cutter is the easiest among the three to file, and it’s also very versatile. It can tolerate dust and dirt better than the chisel cutter. You can file it with a file and guide. If you need a chin that cuts smoothly, you should consider the chipper cutter; it has a curved end view.

Semi-Chisel (Square Tooth, Round Grind)

The semi-chisel is not as aggressive as the chisel type. A round file with a guide can be used to file it. It stays sharp for longer periods and tolerates dirt and dust better than any other two cutters.

Chisel (Square Tooth, Square Grind)

The chisel cutter is a highly aggressive cutter, and you should only use it if you are an experienced sawyer. The chisel cutter is suitable for commercial timber harvesting. It has a square end view. To file it, you need a file that will fit the square shape of the cutting edge. You cannot use the file with a guide to sharpening the chisel cutter. If the chisel is round-ground, then you can file it with a round file. The chisel cutter dulls faster especially when used in a dusty and or dirty environment. The chisel is not the best for climbing or brushing because of the risk of kickbacks.

How to Determine File Size for Chainsaw Chain

To determine the right file size for your chainsaw, you need to read the number marked on the side of the cutter of the chain. You then match that number to the file size that is listed on the file chart. Alternatively, you can measure the pitch of the chain. The pitch is measured in inches. First, you need to measure the distance between three rivets in millimeters. Measure from the center of the first rivet to the center of the third rivet, then divide that distance by two. Multiply the result by 0.039 to convert it to inches. You can then use the chart to get the right file.

Measuring the pitch

Length between tooth rivets divided by 2. see image below:

Chainsaw chain pitch

What Size File Do I Need For My Chainsaw?

Once you have the pitch, use the file chart to get the right file designed for that cutter’s pitch. It is important to keep in mind that even though two chain cutters might have the same pitch, they might need different files if they are not the same type. For example, a chisel cutter needs a file that can fit its square cutting edge. If it’s a chipper cutter, it needs a round file. When filing the cutter, only use round files to sharpen the top-plate and side-plate. When filing the depth gauge, only a flat file should be used so as to maintain its shape.

File Chart

chainsaw file chart

A file chart is used to determine the size of the file that will sharpen the cutter correctly. The file size simply matches the depth gauge code number, alternative depth gauge markings, or pitch of a chain to the right file size. The pitch of a file is the distance measured between three rivets, then divided by two and it is indicated in inches.

Different Types of Chainsaw Files and Gauges

Chainsaw File Size

The main types of files are the 4mm, 4.8mm, and the 5.5mm files. These files can either flat files or round files depending on the cutter you are sharpening. If you have a chain with a chipper cutter, you will go for a round file. If the cutter has a pitch of 5.5mm, you will get a 5.5mm round file. If the chain has a chisel cutter, you will need a flat file. If the chisel cutter has a pitch of 5.5mm, you will choose a 5.5mm flat file, and so on.

Flat File and Gauge

chainsaw depth gauge

The gauges are tools that you use to check the cutter length, top plate angle, and setting the correct depth gauge before filing. They are available in four main sizes. These are 0.43 inches, 0.050 inches, 0.058 inches, and 0.063 inches. It is recommended that you do not file the depth gauges to below 0 .025 inches. The cutter’s depth gauge determines how deep the chain cuts.

The 0.050 inches is the most common gauge. Filing them lower than that will shorten the service life of the chain. The depth gauges should also be filed evenly throughout the gauge. Failure to do so will cause the chain to vibrate and cut rough, or cut crooked.

Gauge Measurement

chainsaw drive link gauge

The gauge measurement is usually displayed on the guide bar of the chainsaw. It is best to use the displayed value to avoid errors that can occur if you try to measure the gauge size manually. If you cannot find the marking, you can use a pair of calipers to take the gauge measurement.

We hope this guide has been helpful and you will have an easy time finding the right chainsaw file size using the chainsaw file size chart. For more on chainsaw chain sharpening see our guide here.