Grass shears come in handy when trimming around fence posts, along garden edging and in other areas where your lawnmower can't reach. Grass shears cut the grass by using a scissoring action. The two blades come in contact near the base of the tool and cut all the way to the tip of the shears. After cutting through many blades of grass, though, grass shears will begin to dull. They may then fold the grass instead of cutting it. When this happens, the shears will need to be sharpened, which is achieved using a few common household tools.
Examine your grass shears. Tighten down the pivot nut with the appropriate-size box wrench. The pivot nut is located where the handles of the grass shears join the blades. Check to see if the shears now cuts grass decently after tightening the pivot nut. If not, you will need to sharpen the blades.
Loosen the pivot nut and separate the blades from each other. Clamp one of the blades in a table vise.
Look at the blade's edge. You should see a factory bevel on the blade. You will need to follow this bevel exactly when sharpening the blade. Take a metal file and hold it firmly in both hands. With one smooth, complete stroke, move the file along the edge of the blade at the same angle of the bevel. Repeat this process until you have a clean, bare-metal sharp edge.
Unclamp the blade from the table vise and clamp the other blade down in the vise. Repeat the sharpening process on this blade.
Tape down a piece of 300-grit sandpaper to a piece of plywood. Take each blade and rub the back of the blade (the non-beveled side) in a circular pattern over the sand paper until the metal burrs are gone. These burrs were formed from filing the blade.
Oil each blade with 3-in-1 oil. Assemble the blades back together and tighten the pivot nut down. Your grass shears are now ready to cut grass.