Even though you cannot always see them, the main feature of our lawnmowers is the blade that is used to cut through the grass on our lawns and bring it all to a uniform length. To ensure that our grass is sliced evenly and not torn out of the ground by blunt blades, however, it is important to keep them sharp. Most lawnmowers will be fitted with one of two different blade types, and here are some tips for keeping them sharp:
This blade type is often found in walk behind lawnmowers and, as they are generally quite large in size, they are completely visible. The knives are evenly spaced on a spiral cylinder that turns as the lawnmower is pushed, shearing any grass that comes into contact with them. The blades in the manual walk behind lawnmower are usually between 8 and 10 inches in diameter and they will only turn as fast as the operator pushes them.
To sharpen these blades, you will need to possess quite a bit of skill to ensure that you get the edges right. This is extremely important, as if a blade of grass is missed by one knife it will not be cut by any of the other knives.
This blade type is found in motorized and ride on lawnmowers and, as they are stored beneath the shell of the machine, they are hidden from view. These knives are rotated at high speeds as the mower moves around the lawn, slicing through any grass that they come into contact with. Whilst lawnmowers for residential use usually only feature one blade, ones for commercial use often feature as many as three of these knives. Each of these knives is generally around 18 inches in length.
To sharpen these blades, you will not require anywhere near as much skill as sharpening reel knives. You are able to do this using a bench grinder or even manually using a metal file, providing that you follow the existing cutting edge of the knife.
Regardless of whether your lawnmower features reel knives or a traditional blade, it is important that you follow a few important tips when cutting your grass. This includes ensuring that your lawn is free of foreign material (like toys, rocks, sticks and so on), as these could potentially damage your blades and require them to be replaced. You should also clean the underside of your lawnmower after use to ensure optimum knife condition.