How to Sharpen a Chainsaw

Step-by-Step Guide

1. 1

   Step 1: Determine the size (or "gauge") of your saw's chain.

   You will need to buy either a rotary grindstone or chainsaw file that matches your chain tooth.
   
   Since there are several sizes of chainsaw teeth, the grindstone or file you choose must be the correct diameter for your saw.
   
   Typical sizes are 3/16, 5/32 and 7/32 of an inch in diameter.
2. 2

   Step 2: Clean the chain thoroughly.

   You may use mineral spirits or a commercial degreasing detergent to remove oil, dirt, and debris from your chain.
   
   Do not flood or get excessive cleaner on the engine or other components, since some of these products can damage the plastic housing or other parts. , Individual teeth may become chipped, broken, or bent, making them dangerous to use.
   
   As a rule of thumb, the top plate (flat surface at the top of cutting teeth) should be at least 1⁄4 inch (0.6 cm) in length.
   
   If it is worn shorter than this, there is a risk it will break while in motion.
   
   Any damaged, weakened, or overly worn chains should be discarded. , The saw must be stable, and the blade must be firmly supported to permit safe and accurate filing.
   
   Clamping the bar in a vise, with the jaws holding the bar and allowing the chain to rotate freely, is your best option. , This will be the shortest cutter on the chain.
   
   If all of the cutters seem to be the same length, you may start anywhere.
   
   The main concern is that you file each cutter so that the flat edge on top of each cutter is very nearly the same length.
   
   That way each will slice away the same amount of wood as they pass through the kerf of your cut.
   
   It also may help to mark the first tooth you file with a dab of paint or a permanent marker so you'll be sure of where you started. , This is the angled "tooth" on the front of the flat surface of the chain link.
   
   The curve of the file should exactly fit the curve of the face of the cutting tip, and the top 20% of the file diameter should be above the top of the tooth. , The angle might be 25 or 30 degrees (check saw specifications).
   
   Special "ripping" chains may have a flatter angle.
   
   In any case, it is essential to match the angle the chain was originally machined to.
   
   Some saw teeth have "witness markers" as a visual aid. , There is some difference of opinion as to the best direction for pushing the file, but usually you will push it from the short side of the angle toward the long point.
   
   This should leave a smoother cutting surface (an important consideration). , As you progress through the chain, keep advancing it by hand so that the tooth you are filing is on top of the bar. , Keep an eye on the length of each flat top of the cutter.
   
   Some manufacturers suggest measuring with calipers to ensure an equal "bite" as the saw is cutting, but if you have a good eye, you should be close enough to get fairly good results. , They should clear each cutting edge about one tenth of an inch lower than the cutter.
   
   This governs the amount of wood that the cutter removes on each pass.
   
   A special tool that is laid on top of the blade is available from chainsaw dealers or hardware stores.
   
   If the gauge is too high and must be filed, this tool protects the adjacent tooth as you file the gauge down. ,,
3. 3

   Step 3: Inspect the chain for damaged or overly worn links and teeth.

4. 4

   Step 4: Set your saw on a solid surface or clamp the bar in a vise.

5. 5

   Step 5: Locate the leading cutter as your starting point.

6. 6

   Step 6: Set your file in the notch on the front of the cutter.

7. 7

   Step 7: Hold the file at the same angle that the cutter was ground or filed to begin with.

8. 8

   Step 8: Slide the file across the face of the cutter

9. 9

   Step 9: using a moderate twisting motion to discharge metal chips (filings) that are removed.

10. 10

    Step 10: Work every second tooth identically from your beginning point around the loop.

11. 11

    Step 11: Reverse sides of the saw and proceed around the unfiled teeth angled in the other direction.

12. 12

    Step 12: Check the clearance of the rakers (depth gauge)

13. 13

    Step 13: the curved hook shaped links between the cutters.

14. 14

    Step 14: File any raker/depth gauge that interferes with the cutter (in other words

15. 15

    Step 15: that sits too high) using a flat mill bastard file (not likely to be needed except when dealing with a defective chain).

16. 16

    Step 16: Oil your chain (saturate/soak with oil)

17. 17

    Step 17: check the tension

18. 18

    Step 18: and you should be ready to cut once again.

Detailed Guide

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