Small projects in the garage

How to sharpen a chainsaw using a hand file

tools you will need, gloves, correct round file, depth gauge, flat file (single cut) and caliper. to make sure you have the correct file size, look the numbers or letters on your chain and consult your manual.

next i mount the saw in my vice

using a digital caliper, i find the shortest tooth, sharpen it, then write down the measurement. this number is what you want to shoot for on all of the teeth on the chain

using a sharpie, i mark the smallest tooth

starting from my tooth marked with the sharpie, i begin to sharpen always starting from the inside out using my right and on the handle and my left on the tip. so in other words sharpen all the teeth that are pointing to the left in this picture. i know its hard to see. the file only cuts on the push stroke. after your push stroke, lift the file off. there are a couple angles which are very important. refer to the last picure on this post. on your cutting stroke you want your file to remain parallel with the top of the tooth. which is appox 90 degrees to the bar. the other angle is the cutting edge. this chain requires a 30 degree angle from the bar. so as you file, you must keep these angles consistent with a slight downward and inward pressure. i'm using a file guide which is not necessary but is useful when first starting to learn. the guide has the 30 degree mark ethced into it and is designed so you can rest it on the top of the tooth and raker. as you file keep checking your tooth length with the caliper. once you come back to the sharpie mark u can now remove your saw and turn it 180 degrees in your vice

with the saw turned 180, i start to file using my left hand on the handle, and my right holding the tip. same thing, file all teeth while checking the length. a sharp tooth will come to a sharp point at the end. you know your saw is dull when it becomes slightly rounded. a beginner may not notice the difference between a sharp saw and slightly dull but if you have some experiance you will notice if your working harder. a sharp saw will rip through a log without you apply much pressure at all to the saw.

once all your teeth are sharp i use a depth gauge to check the height of the rakers. the gauge must be held flat accross the teeth to get an accurate measurement. if the raker sticks above the depth gauge it must be filled down to get the correct depth of 0.025". using your flat file start at your sharpie mark.

the flat file must be used in the same direction as your round file. so go around filling your depth gauges in the same order your sharpened your teeth.

after your depth gauges are filled to correct height, take your flat file again and round your raker slightly.correct angle

correct angle


3 responses

  1. Ken

    Thanks Jonathan! This is very helpful. I’ll give it a try and let you know how I make out. Hope you leave this one here for a while as this will come in handy for us over the hill forgetful folks 🙂

    January 31, 2012 at 1:11 am

  2. Ken

    Hey Jonathan,

    I sharpened the chainsaw last night and tried it out tonight. It’s cutting again. Yeah!
    Took a shortcut by only sharpening the teeth but had good results with just this. Will do it again and eventually do the complete job. Thanks for posting this!


    February 1, 2012 at 2:27 am

  3. Ken, glad it helped. the rakers only need be checked after a few sharpenings. bring it on sunday and we can check it out.


    February 1, 2012 at 12:51 pm

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