How to sharpen a chain saw

There a several tell-tell signs of when you should sharpen your chainsaw.  One is when your arms start cramping up from having to apply to much pressure to make the saw cut.  A properly sharpened saw should pull itself down through the cut.  Another sign to look for is when the saw is discharging dust instead of wood chips.

The best place to sharpen your saw is in the workshop.  It is difficult to do in the field, but can be done.  Many pro’s bring several chains with them and simply replace a dull chain with a sharp one. 

I find it useful to set up a work area on your work bench.  I use a 4x4 board and clamp it down to the table and let the bar rest against it as I sharpen the teeth.  It is also helpful to put a smaller block of wood under the bar to keep the blade from having up and down movement.

Because you'll be working around razor-sharp cutting edges, leather gloves are a advisable.

Ensure you have the proper size file before starting.  Typically, 1/4- and 3/8-inch-pitch, low-profile chains call for a 5/32-inch file; 0.325-inch-pitch chains require a 3/16-inch file; and standard 3/8-inch-pitch and 0.404-inch-pitch chains demand a 7/32-inch file.   Check your chain-saw owner's manual or saw-chain instruction sheet to determine the correct file diameter. If you're not sure, ask your dealer. He also may have literature showing the proper filing angles and special procedures for your chain.

It is essential to remove all damage from the side plate and top plates of the cutting teeth.  Equally important is the top corner of the teeth; ensure it is really sharp.  For good results, you must consistently hold the file at the correct height and orientation within each cutter.

Hold the file with both hands. File from inside the cutter to outside using full strokes. Apply light pressure and let up on the return stroke. Remember, a file only cuts in one direction.   It is very important to have about 20 percent of the file diameter above the top plate.  File all the right hand cutters on one the chain first then do the left hand cutters.  This will help your consistency while filing.

If the file is too high or too large will put back slope on the cutter. Back-sloped cutters do not feed properly, and must forced to cut. Using files held too low or files that are too small create hooked cutters. These end up being dangerously aggressive at first but dull quickly. Using the proper size file and file guide eliminates these common sharpening errors.

File each cutter until you've removed all signs of damage. Keep in mind, the uppermost corner must be very sharp. Making sure right- and left-hand cutters are equally sharp and that their top plates are similar in angle and length will prevent the saw from trying to pull to one side when cutting.

For best results, always follow the manufacturer's recommendations.  For those who understand the principles and use the right tools, Chainsaw sharpening is easily and quickly accomplished.  A properly maintained chain saw will make all the difference when it is time to use it.