How to Sharpen an Ax or Hatchet
To sharpen an axe, use a mill bastard file at least 10 inches long with a handle. Wear leather gloves while filing.
To prevent hitting your fingers on the axe's edge, always file from the back of the axe head towards the edge. File at an angle towards the middle of the blade using strokes from your shoulder. Do not file straight at the edge. Filing straight on will cause causes a rough uneven file marks.
Follow the rounded contour of the axe head. Don’t file too much away from the corners of the axe, since that’s the weakest part of the blade and most likely to chip
On the return stroke, do not make contact with the blade and don’t drag the file back. Dragging the file back dulls the teeth and once it’s dull you can’t re-sharpen it.
Once the axe is sharp on one side, flip and repeat the steps with the file on the other side.
Stop often and clean particles in the file with a wire brush. The teeth of your file will quickly become clogged with shavings from the axe as you work. The teeth need to be clean to be effective.