Sharpening the Saw Chain

A guide to the essentials of sharpening a saw chain correctly.

Each chain pitch is assigned to a specific round file diameter.
Only use specially designed saw chain sharpening files. Your STIHL servicing dealer has a wide selection of high quality files.

Hold the file handle firmly with one hand and guide the file with the other hand across the cutter on the forward stroke.
Start with the master cutter and position the file so that you can apply pressure and file from the inside to the outside of the cutter.

Always hold the file at a right angle (90°) to the guide bar.
The file only sharpens on the forward stroke – lift the file off the cutter on the backstroke.
Rotate the file a little at regular intervals while filing to avoid one-sided wear.

STIHL saw chains are generally filed to an angle of 30° – parallel to the service mark for the filing angle.

The cutting edge is properly sharpened when it is uniformly bright
File all the cutters in that row to the same length, then turn the chainsaw 180° and file all the cutters in the other row. All cutters must be the same length as the master cutter.

On saw chains with humped drive links the hump is lowered along with the depth gauge.

File the top of the depth gauge parallel to the service mark – but do not lower the highest point of the depth gauge in this process. Take care not to touch the freshly sharpened cutter with the flat file.

Before you start sharpening, mark one cutter with a felt tip pen. After two or three strokes of the file, check how much material has been removed. If the surface looks uniform, your filing action is correct.
If there are still patches of color in places, check that you are using the right file and make sure you are not holding the file too high or too low.
The depth gauge setting may be increased by up to 0.2 mm for cutting soft wood in mild weather conditions – no frost. The filing gauge for the next chain pitch up may be used for this purpose.
Never continue working with a blunt chain. A few strokes of the file at regular intervals quickly restores full sharpness.
Count the number of file strokes and use the same number on each cutter to obtain cutters of identical length.
If you find that the cutters in one row are shorter than those in the other row, you have used more pressure while filing the row concerned. Correct the length by with an additional one or two strokes of the file on the longer cutters.