Hand-sharpening your blades with a file takes a little bit of know-how and some practice, but is not hard to master. It can also transform a slow cutting chainsaw into a fast fire-cutting machine.
Not sure if your blade needs sharpening or not? See here.
First of all, engage the chain brake on the chainsaw and lightly clamp the bar in a vice.
Select the diameter of the round file that is appropriate to your chain pitch [that’s the second file down in the image of Needed Tools above]. Check your owner’s manual for your saw’s requirement. Do not use a standard rattail file, as it is tapered and its coarse teeth will ruin the chain’s cutters.
Chain saw files are inexpensive but wear-out quickly. If you don’t feel the blade of the file biting into the metal of the chainsaw blade it is probably worn out.
Hold the file handle firmly with one hand and guide the file with the other hand across the cutter blade. Always hold the file at a right angle vertically to the guide bar [parallel to the ground]. Then hold the file at a 30-35 degrees angle [check your saw’s cutters].
File guides can be used to ensure that you file the same angle on each cutter. They take a little bit longer to use, but they make sure you are restoring the cutting edge to the factory-ground angle.
Remember to only file in one direction- away from you and lift the file off the cutter on the backstroke. Do the same number of strokes on each cutter. Slightly rotate the file a little every few strokes to avoid one-side wear.
After 2 or 3 steady even strokes the face of the cutter should be a shiny silver [if there are any dark spots do another stroke or two]. After sharpening several [5-6] cutters, release the chain break to allow rotation of the chain forward to access more dull cutters to sharpen, then reset the break. Wear gloves to advance the chain. You may want to remove the glove on the hand holding the file while actually sharpening the blade in order to have a better “feel” of what you are doing.
When you are finished sharpening the cutters on one side of the chain, flip the chainsaw around 180 degrees so that you can sharpen the cutters on the other side of the chain.
After you sharpen the cutters, you need to check the depth gauge tips. The depth gauge’s tip controls how deep the cutter can bite and should be a hair shorter than the top of the cutter.You can use a depth-gauge guide to check the height.
After several sharpenings, the cutters can become the same height as the depth gauges and this prevents the saw from cutting. If this is the case, take a flat file and lower the height of the depth gauges to the appropriate height.
After you sharpen your chain, make sure it’s adjusted to the proper tension to avoid ruining the bar or sprocket. To adjust your chain tension, loosen the large nut[s] on the side of the bar cover and then use a screwdriver to turn the tensioning screw on the saw itself. Righty tighty, lefty loosey. You should be able to pull the chain about 1/8 to 1/4 inch from the bar and have it snap back into place when you release it.
If you are still feeling unsure about sharpening your chain yourself, simply take it to a pro. They will use a power sharpener that precisely regrinds each cutter in a uniform fashion. Our Repair Center is an authorized repair center for all Stihl tools.
TIP: Keep the chain off the ground and out of dirt or it will dull very quickly. If the cutters are in direct contact with rocks and dirt, you may need to have the blade sharpened professionally or buy a new one.