18" .325"Pitch .063" Gauge 68 DL Standard Chain Compatible with For Stihl MS250 MS 251 MS361 MS391 Chainsaw #501 84 17-68 - Hipa GA2778B

How to sharpen your chain by yourself

To get the sharpest cutting edge:-File from the inside edge of the cutter, toward the outside edge.

To file the individual cutters: -Position yourself on one side of the saw bar and file the cutters on the opposite side of the chain. A round file sharpens in one direction only—on the stroke away from you.

To sharpen the cutting corner:-Hold the file horizontally and follow the angle of the cutting corner as you lightly but firmly push the file. Then lift the file up to return to the starting position and push it again.