How to Efficiently Sharpen Your Spade

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Who wants to use a blunt tool? It poses more danger than a sharp one, to be honest! Sharpening your spade might seem useless for most, but in reality, doing it can make a big difference. It will allow you cut through roots, sod, and soil easily. Using a sharp blade will do wonders so give it a chance! It isn’t difficult and expensive. In fact, after a few practices, you’ll surely get a hang of it.

So without further ado, let me begin with what you need for this task:

  • 8” – 12” mill bastard file
  • Clamps or vice
  • Eye protection
  • Gloves
  • Grinder
  • Rust preventer
  • Steel wool


  1. Keep the spade in place. Use the clamps to keep the spade horizontally steady for sharpening. Use any style of clamp. Just be sure it can firmly hold the spade and that the blade is facing up. Double check its steadiness. You wouldn’t want it to keep moving around while you sharpen. It will prevent you from keeping the correct angle when you file and can even cause injuries. If clamps aren’t available, you have to ask someone else to hold it in place.

  1. Ensure that your spade is free from rust. Filing a rusty surface will just dull the file, so you need to make sure it’s rust-free. To do this, be sure you’re wearing safety glasses first. Now scrape off the rust first then use a steel wool afterward. If the blade is really jam-packed with rust, attach a wire brush to a drill bit to make the rust removal task faster. After removing all the rust, apply a thin layer of oil or synthetic lubricants such as Tri-Flow, Boeshield T-9, or WD40. Doing this will help forestall the building up of rust.

  1. Examine the edge of the spade. Take a good look at the edge of your spade. Is it dinged up? Does it look like it’s almost 100% flat? Does it seem beveled on both sides? If it is, you’ll have to make use of the grinder to divert its shape. You can still sharpen the blade with a file of you don’t have a grinder.

  1. Sharpen the spade with a grinder. Wear goggles and hearing protection before you start working. You can make use of a bench grinder, which is larger and securely affixed to a work bench, or a hand-held grinder, which can be a 4-inch angle grinder. Any of the two will efficiently work when used with a medium-grit aluminum oxide wheel. When you’re working, ensure that the sparks coming off the grinder won’t fly toward you but toward the shovel. Remember that a grinder will make the edge of your spade rough so you need to touch it up with a mill file. I’ll discuss that in the next steps.

Short Background on Mill Files:

A mill file is the most popular and common file shape. It’s a rectangular file that slightly tapers in both thickness and width from the end of the handle to its other end.

When people talk about the “cut of a file”, that refers to the fineness of its teeth. The cuts are classified into the following:

  • Dead smooth

  • Smooth

  • Second cut

  • Bastard

  • Middle

  • Rough

A single-cut contains a single set of parallel teeth, while a double-cut has a second set of cuts that crisscross the first.

Let’s talk about what type of file you should use. Files from Corona are mill bastard files. For this particular task, you’ll be needing a bastard mill file that’s 10-12 inches long. Bear in mind that the file should have a flat, wide edge with a single-cut teeth pattern that’s rough. With this, you can remove enough material without doing it excessively.

Single-cut files may take more elbow grease but they allow more control. Double-cut ones, however, are best for rougher jobs since they remove more material with every pass.

You can actually settle with 8-inch long files since they remove more metal with every pass. The handle is separated so be sure to put it on before using the file.

Now, what side of the spade should you file? The top side that handles the soil when you lift the spade up. This part should be a bevel.

That was a lot of information! Why don’t you stand up first and relax a bit before we move on? It’s important to understand the next steps so be sure you can still focus! If not, walk around or drink water first.

Ready for the fifth step? Here it is.

  1. Hold the file with your hands, making sure that the handle is toward you and that the file’s flat edge is against the edge of the spade at a similar angle as the bevel. If there is no bevel on the edge of the spade, hold the file at 45 degrees to the flat surface of the blade. Remember not to pull the file toward you, this act will bend the teeth of the file and damage it permanently. Next, with the whole length of the file, push down while you’re moving it forward. Just use light or no pressure on the backstroke. Ensure that your strokes are even and straight while working on your way from one side to another, instead of doing it to one spot several times. Hold the file so that it’s a little slant. This will allow you to move it a bit sideways when you push it forward. Make sure you’re filing at about 45 degrees. What gives a sturdier edge than a low angle is a steep angle. However, it is less sharp. To make it easier for you, just try to have a ¼ inch of new metal showing when you’re done sharpening. Or if the original bevel can be seen, try to maintain the same angle when you file. Your aim is to make the blade sharp enough to cut through roots, soil, and sod with ease but not to make it too sharp for you. Be cautious of the tiny pieces that stick out along the edge. They can cut you if they aren’t filed off.

  1. Get rid of the burr. You can find the burrs by vigilantly running your finger across the edge along the underside. You can flip the spade and remove the burr by laying the file flat along the back portion of the spade and drawing it slowly and carefully toward you. Don’t round over the edge you’ve just finished filing. Removing it the burr won’t take a lot of strokes. A few will do.

  1. Clean the file. Remove the metal filings from the spade that built up between the teeth of the file by dipping the file in water. If you don’t clean the file, it cannot cut efficiently. You can even use a file card for this step. It’s a brush which consists of metal bristles. Be careful not to knock the file against a hard surface just to forcefully remove the fillings. You’ll end up damaging it if you do that.

That’s it! The instructions may be long, but the result of following this step is satisfying! Plus, a sharp blade will make your job easier so performing these isn’t a waste of your time.