How to Sharpen a Chainsaw: The Comprehensive Guide

Before You Start: Is This Chain Worth Saving?

Sharpening is an essential skill for every chainsaw owner. However, there is a point of diminishing returns. Before you spend 20 minutes filing, inspect your chain.

It is often more economical to replace the chain if:

  • You hit a rock/dirt: If the cutting teeth are jagged or crushed, hand filing will take hours to correct.
  • The teeth are short: If the cutting tooth is less than 4mm long (or past the witness mark), the chain is at the end of its life.
  • The drive links are burred: If the bottom of the chain (that sits in the bar) is damaged, it will ruin your bar groove.

Take a look at our range of new chainsaw chains here.

The Guide: How to Sharpen Your Chain Manually

If your chain is in decent condition and just needs a "touch-up," here is how to restore that razor edge.

1. Identify Your Chain Pitch & File Size

You cannot use just any file. You must match the file size to your chain's "pitch" (the distance between rivets).

  • 3/8" LP (Low Profile): Requires a 5/32" (4.0mm) file. (Common on small saws).
  • 325" Pitch: Requires a 3/16" (4.8mm) file. (Common on farm saws).
  • 3/8" Standard: Requires a 7/32" (5.2mm) file. (Common on large pro saws).

Note: If you aren't sure, check the number stamped on your drive link and cross-reference it with our [Chain Finder Tool].

2. Tension and Secure

Tighten your chain slightly more than usual so it doesn't wobble while filing. Clamp the guide bar in a vice to keep it steady. If you are in the bush, cut a deep notch in a stump and sit the saw bar in it to hold it still.

3. The Angles Matter

This is where most people go wrong.

  • File Angle: Hold the file at a 30° angle to the bar (or 25° for some ripping chains). Most teeth have a small line stamped on top—simply keep your file parallel to that line.
  • Vertical Angle: Keep the file flat (90°) relative to the side of the bar. Do not dip the handle down or lift it up.

4. The Stroke

  • Push Only: Files only cut on the push stroke. Do not drag the file back. Lift it up on the return.
  • Count Your Strokes: Consistency is key. If you do 5 strokes on one tooth, do 5 strokes on all of them. This keeps the cutter lengths equal and prevents the saw from cutting in circles.
  • Rotation: Twist the file slightly as you push to clear the metal shavings.

5. Don't Forget the Depth Gauges (Rakers)

The little metal bumps in front of the sharp tooth determine how deep the tooth bites.

  • If they are too high, the saw creates dust (not chips) and won't cut.
  • If they are too low, the saw grabs and kicks back (dangerous).
  • The Fix: Every 3–4 sharpens, run a flat file over the rakers using a depth gauge tool to reset them to the correct height.

The Verdict: Sharpen or Replace?

Mastering the file is a point of pride and necessary for quick touch-ups in the field.

However, if you are struggling to get a good edge, or if your chain has hit the dirt, the frustration isn't worth it. A fresh Alpine Semi Chisel Chain comes factory-ground to the perfect angle, ready to tackle Australian hardwood right out of the box.

Pro Tip: Many of our customers keep a "stump chain" (an old chain for dirty work) and a brand new "clean wood chain" for the big logs.

[Shop Alpine Chains Now - Prices Start at $XX]