Easily Sharpen Your Lawn Mower Blades With These Tools From Harbor Freight

Harbor Freight seems like the kind of place you should be able to walk right in, grab an implement for sharpening a lawn mower blade, and in no time be back on your lawn and struggling to get the blade retainer bolt off. And, in a way, it is, but there are multiple ways you can sharpen lawn mower blades; you have choices. The tool retailer offers many options, from angle grinders to belt sanders. The question is, which one is best for you?

The most obvious, old-school approach would be to use a metal file. Typically, what's needed for sharpening mower blade steel is a 10-12-inch American-pattern mill file. This is the coarsest grade of hand files and is usually a flat, tapered, single-cut file designed to remove material from steel aggressively, making it an excellent choice for sharpening lawn mower blades. You should be able to sharpen a mildly dulled mower blade with 20-30 strokes of such a file. Harbor Freight comes close enough, with a five-piece set of Pittsburgh 12-inch files ($9.99) that includes heat-treated steel files that will do the trick.

Angle grinders are a popular choice for sharpening lawn mower blades. They're available as corded or battery-powered tools. Harbor Freight offers both options, and the cost ranges from $14.99 to $129.99, with an upper limit of $99.99 in the 4 ½-inch range. A simple DIY option for sharpening lawn mower blades is the combination of an angle grinder and a flap disc abrasive wheel. Harbor Freight sells tough type 29 ceramic grain flap discs in 36, 60, 80, and 120 grit options for $12.99.

Bench grinders may be the most traditional way for DIYers to sharpen lawn mower blades, though they have fallen out of favor a bit in recent years. While this is a freehand operation like using an angle grinder, one important difference is that you hold the blade against a fixed grinder rather than the other way around. With a properly set-up tool rest, it's a stable, predictable, and effective method. The Bauer 8-inch Bench Grinder has dual spark shields, an LED light, and a 4.8-amp, ¾-horsepower motor, and should do the job nicely.

Harbor Freight offers a couple of other common options for sharpening mower blades, and one of them is another grinder. Right-angle pneumatic die grinders are functionally similar to angle grinders, with a slightly different attachment angle. They are powered by compressed air. Die grinders are faster than metal files for sharpening lawn mower blades and are comparable to angle and bench grinders. Right-angle die grinders are more natural than straight grinders for sharpening blades, and Harbor Freight offers a selection from $24.99 to $59.99, including the $44.99 Chief 1/4 in. professional mini die grinder, a compact tool with an aluminum body, adjustable speed, and front exhaust for safety and better working view.

You can also manage light blade sharpening with a rotary tool. This is a smart way to sharpen mower blades when you need a quick blade touch-up. The Bauer 1.6-amp rotary tool kit ($79.99) is variable speed, includes a convenient 36-inch flex shaft, and comes with a variety of attachments and accessories, including a garden tool sharpening guide and grinding stones. That the sharpening guide's slot is most likely too small for a mower blade, so you'll need to use it freehand. 

Finally, a belt sander is a competent tool for sharpening mower blades, and Harbor Freight has a selection of belt sanders. The Bauer 4-by-36-inch belt sander ($114.99) is a combination belt and disc sander with a steel body and a 90-degree adjustable belt tilt. Harbor Freight also sells a combination 8-inch bench grinder and belt sander ($169.99) under its Bauer brand.