Sharpen Drill Bits In A Pinch Without Power Tools Or Grinders

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I've been a woodworker and remodeler for 25 years, and while some argue that a dedicated tool is the best way to sharpen dull drill bits, I still often turn to other options. When I'm in the workshop, for example, I sometimes use a bench grinder because it has a rest that keeps the bit at the right angle. I use the same machine for sharpening my chisels and even my lawn mower blades. However, if I'm away from the workshop and I discover a blunt drill bit, I'm going to need to do the job by hand. In a pinch, I use aluminum oxide paper.

This abrasive paper is what you typically use for refurbishing furniture or finishing beginner woodworking projects. While it might not seem substantial for sharpening a steel drill bit, it absolutely can do this, too. Aluminum oxide is actually the same stuff many grinding wheels are made from — but in this case, it's bonded to paper.

When it comes to sharpening your drill bits, 80 grit is a good choice, and there are a couple of techniques to try. Some people wrap the abrasive around a file and rub that against the end of the drill bit. I find it difficult to apply enough pressure and maintain the correct angle with this method. Instead, I wrap the abrasive around a piece of plywood or hold it against a hard, flat surface and rub the drill bit across it. When doing this, be sure to turn the drill bit every few strokes to sharpen both cutting edges. This strategy might not be the most effective or ideal, but it does the job when you have no alternative.

Aluminum oxide typically doesn't have a problem sharpening ordinary twist drill bits made from hard, high-speed steel. However, some top-rated drill bit sets with drills made from much harder materials, such as cobalt, titanium, tungsten carbide, and diamond-tipped versions, are too tough for aluminum oxide to sharpen. In fact, even on a bench grinder, you'd need a special wheel to sharpen these materials.

A number of drill bits also come in less common shapes. A paddle bit (also called a spade bit) has a central spur to guide it. The technique I described with aluminum oxide will just about work, but it can feel awkward because of this. There are also hole saws, saw-tooth bits, and forstner bits that have sharp teeth or circular blades for cutting. As a result, sharpening these requires a different approach — using diamond-encrusted files.

The EZE-LAP Forstner Bit Sharpening Kit is great for on-the-go projects and includes flat and triangular files that can be used to sharpen a variety of bits and, at around $25 at the time of writing, is well worth the investment if you use these types of drill bits often.