Lawn Mower Blade Sharpening

How To Sharpen Lawn Mower Blades

How To Sharpen A Lawn Mower Blade

Mobile Alabama Sharpening Service
How To Sharpen Lawn Mower Blades


There’s a lot of methods used to sharpen lawn mower blades. There are almost as many techniques for sharpening blades as there are ways to cut yourself while sharpening. Almost! Not intended to be a little bit of humor, that opening sentence is just to provide a bit of information you should be aware of: the bacteria that causes tetanus are found in soil, dust and animal feces. This information comes from the Mayo Clinic which I quote here:

The bacteria that cause tetanus, Clostridium tetani, are found in soil, dust and animal feces. When they enter a deep flesh wound, spores of the bacteria may produce a powerful toxin, tetanospasmin, which actively impairs your motor neurons, nerves that control your muscles. The effect of the toxin on your motor neurons can cause muscle stiffness and spasms — the major signs of tetanus.

 Every lawn I’ve ever seen had some soil, dust and animal feces. So, if you work outside and especially if you work with hand tools and sharpening instruments, keep that tetanus shot current. And, one more thing, you probably treat your lawn mower and lawn mower blade sharpening way to casually. In 2010, 253,000 people were treated for lawn mower-related injuries, according to the U.S. Consumer Product Safety Commission. Children under age 19 account for nearly 17,000 of these injuries. The number of lawn mower-related injuries increased 3 percent since 2009.
I’m not passing on this info for its “scare factor.” It’s just that you need to be careful. As far as trying to convince you that you need to let me handle the job, that’s really not the case either. In fact, being a firm believer in self-sufficiency, I think you really should do your lawn mower blade sharpening yourself or at least know how to do it. Lawn mower blade sharpening is easy – really easy. It can be difficult to remove the blades and its usually always a dirty job but nonetheless any guy or gal should be able to do this. Now, let’s get on with it:
  1. Know your objective. You do not want the lawn mower blade to be super sharp. The edge should be more like a butter knife.
  2. Remove the blade from the mower. I know it can be sharpened while on the mower but the very important visual inspection of the blade cannot be complete unless you view each side of the blade. You are looking for hair-line fractures or anything that lessens the integrity of the blade. Clean the blade of dirt, rust and grass if needed so you can clearly see any small fractures. If anything at all looks like a crack (usually indicated by a dark line that cannot be easily removed), discard the blade. Save it for my scrap metal bin.
  3. Clamp the blade in a vise or use some other method to secure the blade so it does not move.
  4. Using your preferred sharpening tool, small low-speed grinder (hand-held), file, rotary tool, etc., grind the cutting edge at the same angle as what you will find on the edge.
  5. Balance the blade. If you need to remove any metal to balance the blade, remove from the back of the blade, not the cutting edge.
  6. Before you decide to sharpen your lawn mower blades, you should first consider the cost effectiveness. I charge $7.00 per blade for sharpening. Obviously, if you can purchase a new blade for little more than $7.00 it just dosen’t make sense to sharpen the old one. However, if your cost is say $10.00 or more you may save a few bucks. Blades that have been maintained and not abused by their owners may be able to be sharpened two times or more. That is a real savings. If you are guilty of mowing sand and gravel pits, tree stumps and other such items, you probably don’t need to call me. Go get a new blade.
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Published: March 4, 2015