One of the easily overlooked aspects of lawn mower maintenance concerns how sharp the mower blade should actually be. There is a tendency for lawn owners to purchase a mower and then neglect sharpening the mower blade, even as they put the machine through taxing use from one season to the next. On the other hand, other lawn mowers sharpen their mower blade relentlessly, making their blade even more razor sharp than it was when they purchased the actual mower. The answer for exactly how sharp the mower blade should be gets lost in a sea of conflicting opinions, as everyone feels they have the right answer. In earlier posts, we discussed in greater detail why sharpening the mower blade is important, so below, we explain how sharp you should keep your mower blade.
Simply put, every lawn owner should pay close attention to their mower blade, as it has a great impact on the performance of their mower. Determining the sharpness of the mower blade is challenging because one must pay close attention to a number of variables. First, if the mower blade is too sharp, it will become dull far more quickly than with a less sharp blade. If a blade has a blunt edge sharper than 1/8 inch, it may also be susceptible to any pebbles or other such residue in the soil—basically, you want your mower blade to at least be able to stand up to the rigors of actually mowing your lawn. At the same time, if your lawn is not particularly rugged, it is also acceptable to have a mower blade that is slightly sharper.
The yard matters
Meanwhile, those who have yards with uneasy terrain and lots of weeds will find that it is especially necessary to resist sharpening the mower blade to an exceptionally fine point. Along this vein, if you use your mower in woodsy areas, it is similarly necessary to keep the mower blade slightly duller. In general, a good rule of thumb is to keep the mower blade at the same sharpness as when it was purchased. This means that the width of the slope should be around double the thickness of the mower blade. Another important tip is that there is really no need to get rid of any marks that may have surfaced on the mower blade; these are cosmetic and will not hinder performance.
As you can see, there is no single answer for how sharp the mower blade should be, and lawn owners need to take into consideration the terrain of their yard. If you keep your blade at the level it was at when you purchased it and remember to sharpen the mower blade twice a season, your mower should be just fine.