One of the best ways to keep your lawn mower cutting like new is to regularly sharpen the blades. Most mower blades will need sharpened at least once a year. Mowers that are used frequently, as is the case with commercial lawn mowers, will need blades sharpened more frequently. Unless blades are bent or otherwise damaged, they can usually be sharpened and reused instead of replaced. However, some manufacturers recommend replacing blades every couple of years to maintain a good cutting edge.
Removing Mower Blades
When removing mower blades so they can be sharpened or replaced, safety is the most important issue. In some mowers, the mower deck can be raised high enough to remove the blades without lifting the mower. For other mowers, or if you want more room to work, the mower will need to be raised and safely secured. Commercial mowers, lawn tractors, and riding mowers are heavy and you want to be certain they will not slip while you are working under them.
To prevent the mower from starting while you are working on it, remove the key from the ignition and disconnect the spark plug. Block the blade with a thick piece of wood, to prevent it from turning, and remove with a wrench of the appropriate size.
Sharpening the Blades
Once the blades are removed, you can sharpen them yourself for take the blades to a service department for sharpening. If you choose to sharpen the blades yourself, the first step after removing the blades from the mower is to secure the blade with a vice or by clamping it to the work service.
Once the blade is secure, the principle goal when sharpening a mower blade is to maintain the same cutting angle that is already on the blade. For blades that are not very dull, a metal file or a hand grinder can be used to achieve the desired edge. When sharpening, remember to grind both blades evenly to maintain balance.
With a severely dulled blade, a bench top grinder will be needed or you can take the blade in for professional sharpening. If using a grinder, simply run the blade perpendicularly across the spinning wheel to remove nicks, then support the blade using the rest of the plate and grind the length of the blade at the existing angle to get a butter-knife-sharp edge.
Replacing Mower Blades
If you are replacing the old blades with new ones, be certain that the new blades are correct for your model of lawn mower. The owners manual for the mower, or a qualified service department, will be able to tell you which type of blade is best. As when removing blades, you’ll want to make sure the mower is raised securely and that the engine will not start up while you are working. Make sure the “fin” of the blade is facing up and that the blades are tightened securely.
Sharpening or replacing mower blades is an important step in regular lawn mower maintenance. Keeping your blades sharp will ensure a higher quality of lawn mowing by cutting grass cleanly, which makes for a more attractive lawn as well as healthier grass.
