wear gloves and eye protection
you will need a file the same size as your chainsaw teeth to ensure you maintain the “hook” of the tooth
you will need a file guide to ensure:
files only file in the forward direction - lift file off rather than filing both ways
ensure chain tension is correct so the tooth doesn't move excessively
preferably have something such as a bench vice to hold the bar (and still allow the chain to freely rotate), this allows you to use two hands on the file
keep filing tooth until it looks sharp and repeat for the other side teeth
check the height of the rakers (the knobs that precede each tooth blade) to ensure they are not too high (very little wood gets cut and wood chips are small or even powdery), or too low (too much wood gets cut resulting in jamming)
the correct height is also determined by whether you are cutting hard wood or soft wood
check the wood chips, if they are very small, you need to file it down
use a flat raker file to file these down as needed - only 2 strokes of the file and then re-check the wood chips
if you file it down too much you will need a new chain
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