How to Sharpen a Lawn Mower Blade

Lawn Mower Blade Sharpening

Before Sharpening Your Lawn Mower Blades with a Blade Grinder

Step 1

Check the work area. Make sure the grinder is properly supported on a flat and level work surface.

Step 2

Make sure that there are no:

Flammable materials such as shop rags, gas cans and other solvents.
Objects or people nearby who are positioned close enough to be hit by sparks or debris.
Loose objects (including your clothing or hair) that could get caught in the grinding wheel.

Step 3

Inspect all aspects of the grinder. If any of the following questions can be answered with a “yes”, do not operate the grinder.

Are there breaks in the insulation or exposed wires on the power cord?
Is the cord’s ground terminal broken or damaged?
Is the stone cracked or chipped?
Are any of the guards missing or damaged?

Using the Lawn Mower Blade Grinder

Note: These instruction are written in order to give a general overview of the steps involved in using a lawn mower blade grinder. They are not intended as a replacement for your blade grinder’s user manual.

Step 1

Determine whether the lawn mower blade is left-handed or right-handed. On a flat surface, lay the blade so that the bottom side of the blade (aka the flat or “grass side”) is down against a flat surface. Position the blade so that it is extending away from you (as if each end were at the “12” and “6” positions on a clock). lf the straight (cutting) edge on the far end is on the right, it is a right-handed blade. If the edge is on the left, it cannot be sharpened with the Oregon 88-025 Lawn Mower Blade Standard Duty grinder. Check your blade grinder manual for details.

Step 2a

Adjust the grinding angle for the blade. The blade to be sharpened will determine the angle the machine is set at. All Oregon blades, are ground at 30 degrees.

FAQs

How Sharp Should Your Mower Blade Be?

Mower blades should be aggressively sharp, but not as sharp as a razor’s edge. You should be able to touch the blade with your hand without getting cut. Contrary to popular belief, a lawn mower blade with a razor sharp edge will not cut grass better. In fact, an edge that is that sharp has the tendency to roll over, which can cause blades to get nicked and chipped. Additionally, lawn mower blades that are too sharp get duller, faster resulting in the need to sharpen more frequently and a shorter blade life.

Warning WARNING: Make sure your lawn mower blade grinder is always turned off before you perform any maintenance.

How Often Should You Sharpen Lawn Mower Blades?

How often you sharpen your lawn mower blades depends on your frequency of use. If your lawn mower is only used at home, you probably only need to sharpen your blades once a year. If you are a professional, you will need to sharpen your blades more frequently. Once you notice a reduction in cutting performance, it’s time to sharpen your mower blades. Damaged blades should be replaced immediately.

What tool do you use to sharpen mower blades?

The best way to sharpen a mower blade is with a dedicated blade grinder. A blade grinder is the best tool to use because it can maintain consistent sharpening angles.