How To Sharpen Your Chainsaw Like A Professional

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A dull chainsaw is dangerous, learn how to sharpen your chainsaw like a pro. With the proper tools and a little know-how it's easy even for a beginner.

Think back to the day you brought your chainsaw home from the home center. Do you remember how it sliced through those trees as if they were made of Balsa? That's the way it should cut every time you take it out and fire it up. It can too with your help. It all starts with you learning how to sharpen the cutting chain like a pro. Sharpening chainsaw like a pro is not rocket science but it does require you to have the right tools and knowledge of how to use those tools correctly.

Degree of difficulty on a scale of 1 to 10 is a solid 3.

You will need the following size round files:

  • A 5/32 inch diameter file for chains with ¼ and 3/8 inch pitches.
  • A 3/16 inch diameter file for chains with a 0.325 inch pitch.
  • A 7/32 inch diameter file for a standard 3/8 inch and 0.404 inch-pitch.

You need to use caution when selecting a file to use with any pitch chain because there are many exceptions to the rules of thumb that I outlined here. For example, some manufacturers require a 3/16 inch or 4.5-mm file to be used with their standard 3/8 inch pitch chain. Always check the service manual that came with your chainsaw. If you have any doubts, call the dealer. The dealers service department can tell you the size file you need to use, and they can also tell you the proper filing angle.

You will need a chain sharpening guide.

After selecting the proper file to use for your chain's pitch, you need to keep the file at the proper angle when sharpening the chain. You will need to purchase a chain sharpening guide. There are three types of sharpening guides, a guide that attaches to file, a guide that slips over the chain and clamps to the saw's cutting bar, and a bench mounted sharpening guide. A guide that clamps to the file is a poor choice because the guide obscures your vision during the filing process. The bench mounted guide is the guide of choice by professionals, but it is overkill for anyone who only uses a chainsaw occasionally. A guide that slips over the chain and clamps to the cutter bar is the best choice for the DIYer. This type of guide provides consisting filing angle and an excellent view of the work being performed.

You will need a depth gauge.

Filing the side plates reduces their overall depth, and it is critical to maintain the proper cutting depth by filing the cutting depth guide periodically, and you need a depth gauge to judge when this is necessary. There is no way around investing in a proper depth gauge. With a little shopping around online, you can have a proper bar mounted sharpening guide, depth gauge, and the proper files for less than $125.

Know when to sharpen your chainsaw chain.

Chainsaw cutters are coated with a thin, extremely tough plating of industrial chrome. Chainsaws would never require sharpening if they were only used to cut clean wood. That is not what happens in the real world. As touch as the industrial chrome plating is, it does not take much to dull the cutters. Cutting into the grit embedded in the wood dulls the chain. Accidentally running the high-speed chain into the frozen ground and striking rocks, when cutting logs lying on the ground will dull a chain in no time flat. So how do you know when to sharpen the chain? Look for these symptoms of a dull chain.

A sharp chainsaw will self-feed. If you have to force the saw into the wood, it needs to be sharpened. Forcing a saw to cut with a dull chain is not only damaging to the saw, it is dangerous.

When the chainsaw starts producing dirty saw dust instead of clean wood chips, it needs to be sharpened.

When the top plates and side plates look shiny, the saw needs to be sharpened. When the chrome plating wears away, the bare steel shines through giving it a shiny appearance. The chain needs to be sharpened to restore the chrome overhang.

Develop the proper sharpening techniques.

  1. Pace the chainsaw on a sturdy surface. Place a block of wood under the cutting bar to keep the chainsaw from teetering back and forth.
  2. Install the sharpening guide on the saw's cutter bar, lay the file in the guide, and align it with the witness marks.
  3. The sharpening guide is adjusted properly if only 20 percent of the file is exposed above the saws top plate. This is important because too much exposure will place a back slope on the cutter. A back slope on the cutter will require you to force the saw to cut just as a dull cutter does. Using a file too large will also result in placing a back slope on the cutters. Too little exposure above the top plate or using too small a file will result in a hook being formed on the cutter resulting in an overly aggressive cutting saw which is a dangerous saw.
  4. Use both hands to file, grasp the handle firmly in one hand and place the other hand on the front of the file. Using firm, full stroke, file from the inside of the cutter outward.
  5. File all the cutters on one side of the chain first and the file all the cutters on the opposite side of the chain. File each cutter until you have removed all signs of damage. The top corners must be truly sharp and cleanly outlined with a chrome plated edge. It is extremely important that all the cutters be equally sharp with the top plates having the same shape or else the saw may pull to one side or the other.
  6. You will need a flat file to file the cutter depth guide. When filing the cutting depth guides,do not file them too low. Filing the cutting depth guides too low will create an overly aggressive cutting saw which is a dangerous saw. Always check the saw's manual for the correct depth to file the cutting guides.


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