How to Sharpen a Chainsaw Chain Properly

How can I tell if a chainsaw chain is dull?

A dull chain often becomes noticeable while you’re sawing. When used correctly, a sharp chain cuts smoothly into the wood and produces distinct chips. As the chain becomes dull, its cutting performance changes.

Typical signs include:

The chain should be inspected as soon as these signs appear.

What file do I need for my saw chain?

To manually sharpen the cutting teeth, you’ll need a round file (Item No. 35470) with the appropriate diameter. The correct file size depends on the saw chain being used and its pitch or design.

You can find the required size in the chain manufacturer’s specifications. Do not use just any round file, as the file’s diameter and position affect the geometry of the cutting tooth.

A file gauge or file guide makes it easier to maintain the intended angle and the correct file position.

Preparing the Chainsaw for Sharpening

Place the chainsaw on a stable work surface and secure it against accidental startup according to the manufacturer’s instructions.

For a secure hold, the guide bar can be clamped in a suitable vise or file block (Item No. 15534), for example. Take care not to damage the guide bar.

The chain should be tensioned so that it lies securely in the guide during filing but can still be moved to work on the remaining cutting teeth in accordance with the manufacturer’s instructions.

1. Clean and Inspect the Chainsaw Chain

First, remove any coarse dirt from the chain and guide bar. Next, inspect the entire chain for damage, cracks, or severely worn parts.

A damaged chain should not simply be resharpened and reused.

2. Identify the Shortest Cutting Tooth

Locate the most worn or shortest cutting tooth. This tooth serves as a reference point for the remaining cutting teeth.

Mark the starting tooth, for example, with a suitable marker. This will help you recognize later when you have sharpened the entire chain once.

3. Maintain the Correct Sharpening Angle

Position the round file against the cutting tooth according to the chain manufacturer’s specifications. The specified sharpening angle must be maintained as consistently as possible.

Different angles may be required depending on the chain type. Therefore, you should always follow the specifications for your specific saw chain.

File holders and sharpening gauges can help you guide the file correctly.

4. File from the inside out

The cutters are usually filed from the inside out. Apply even pressure and guide the file in a controlled manner along the cutter.

The round file does the work during the forward stroke. It is relieved of pressure during the return stroke.

Try to file each cutter with a similar number of even strokes.

5. Work on one side of the teeth first

The cutting teeth on a chainsaw chain alternate between pointing left and right. Therefore, it is practical to first work on all the cutting teeth in one direction.

Next, adjust the chainsaw or your working position accordingly and sharpen the opposite row of teeth.

This makes it easier to maintain the intended angle consistently.

6. Ensure uniform tooth lengths

After sharpening, all cutting teeth should be as uniform in length as possible. Significant differences can cause the chain to cut erratically or unevenly on one side.

Use the shortest cutting tooth you identified earlier and the manufacturer’s specifications as a guide.

Checking the Depth Gauge

In addition to the cutting teeth themselves, the saw chain has what are known as depth gauges. They help determine how deeply the cutting tooth can penetrate the wood.

Repeated sharpening causes the cutting teeth to become shorter. Therefore, the distance to the depth gauge must also be checked at regular intervals.

A depth gauge is suitable for this purpose. If reworking is necessary, it should be done with a suitable flat file in accordance with the chain manufacturer’s specifications.

Important: A depth limiter that has been filed down too much can adversely affect the chainsaw’s running and kickback behavior. Therefore, never remove more material than necessary based on visual judgment alone.

How often does a chainsaw chain need to be sharpened?

There is no set interval for this. How quickly a chain becomes dull depends, among other things, on the type of wood, dirt buildup, working methods, and possible contact with foreign objects.

The cutting edge can become dull particularly quickly due to contact with soil, sand, or stones. Even brief contact with the ground can significantly reduce cutting performance.

It is therefore better to lightly resharpen the chain early on than to continue working for a long time with a chain that is noticeably dull.

Hand file or chain sharpener?

Round files and file holders are a simple solution for regular resharpening on the go or in the workshop.

If you frequently sharpen multiple saw chains, you can alternatively use an electric chain sharpener (Item No. 97192 or 26847). This allows you to adjust the angle and material removal consistently. However, you must work carefully here as well to avoid removing an unnecessary amount of material from the cutting tooth.

For occasional touch-ups, a suitable file set is often sufficient.

Avoiding Mistakes When Sharpening

Some common mistakes can impair cutting performance or shorten the service life of the saw chain:

Filing gauges and guiding aids are particularly recommended for your first sharpening attempts.

Check the Chain After Sharpening

Once the work is complete, the entire saw chain should be checked again. Make sure there is no visible damage and that all the cutting teeth that were worked on have been sharpened evenly.

Next, adjust the chain tension according to the owner’s manual. Also check the chain lubrication and the condition of the guide bar.

Only then should the chainsaw be prepared for use again.