Most DIYers will use a drill bit set to make small holes in steel, wood, and plastic — nothing more. However, several other bit types can do many jobs on many materials, provided you choose the right drill bit for the job. We’re listing a few unique drill bits that do a rather specialized job.

While many of these bits are designed to make boreholes, these aren’t the usual pinpoints you put in wood and other materials to place a tiny screw. Instead, they’re designed to make larger holes for different projects, such as plug compartments or angled holes for joining materials at right angles. 

One of the strongest ways of putting two pieces of wood together is through pocket hole joinery. This method uses a pocket hole that’s drilled at an angle, forming a “pocket” for the screw. This would then allow the screw to mechanically secure the two pieces together while remaining discreet (provided that the hole is drilled on the interior part of the joinery) or hidden (if you use plugs to hide the holes).

To do this, you need a pocket hole jig to avoid errors, especially if the material you’re working on moves while you’re drilling. It’s better to use the specialized stepped drill bit to drill the pocket hole. That’s because a stepped drill bit has a smaller diameter tip, allowing it to drill a pilot hole where your screw will fit in. The rest of the stepped drill bit has a larger diameter that removes more material, creating a “pocket” that will hide the screwhead. This makes it a perfect addition to your toolkit for making these beginner-friendly woodworking projects.

While you can theoretically drill a pocket hole without a stepped drill bit, this is a much more involved process. You’d need two drill bits — a thinner one for the pilot hole, and a thicker bit for drilling to the pocket itself. That means you’ll have to drill twice, increasing your chances of slipping and making a mistake.

Traditional drill bits are good at boring tiny holes for inserting screws, but they’re inadequate for larger fixtures. For example, if you’re making a cabinet door or want to put a desk grommet on your solid wood desk to run wires through, an ordinary drill bit won’t do. In that case, you need a Forstner bit, especially if you want to create a flat-bottomed hole for mounting hinges and making dowel joints or need to make a clean, precise cut on expensive hardwood.

A spade bit can do the same job as a Forstner bit, allowing you to create holes in your material that aren’t through and through. However, they’re only capable of making rough cuts, meaning they’re unsuitable for jobs that require a fine, high-quality finish. You can also use a hole saw to drill large holes, but this type of bit cannot make flat-bottomed holes, making it unsuitable for some applications. 

If you want the best of both worlds, a Forstner bit is a good addition to your drill bit collection alongside these useful Makita tools for making custom cabinets and other woodworking projects.

If you want to cut a large hole in brick, concrete, or other masonry, use a coring drill bit. This is a hollow, cylindrical tool with sharp teeth at the drilling edge. Since this is a hollow bit, its maximum drilling depth is limited by the length of the cylinder. Once the tool hits its maximum reach, you’ll have to remove the coring drill bit and extract the core (or the material left behind by the bit) before you can start working again.

There are two common types of coring drill bits — carbide and diamond. Carbide coring drill bits are often the cheaper option, as they use tungsten carbide teeth. While they’re good enough for going through masonry, they’ll struggle if you hit other materials like steel rebar. Furthermore, they don’t cut as cleanly as the latter, which have a diamond-encrusted edge that allows for cleaner cuts. 

Diamond coring bits can easily cut through steel rebar without immediate dulling, but you will have to cool the drill by pausing occasionally or using a water-cooling system.

You cannot rely on bits designed for wood or masonry for drilling a large-diameter hole in metal. Instead, you need a specialized annular cutter drill bit. These bits’ sharp, cylindrical design may seem no different from hole saws and coring bits, but those won’t cut large holes through aluminum, steel, and other similar materials.

The annular cutter drill bit is known for its clean, precise cuts, resulting in smooth edges on the cut metal. This means you don’t need to deburr or ream the edges, saving you time, effort, and damage to wires, cables, and whatever else you may pull through the hole.

Just like coring drill bits, annular cutter drill bits are available in two types — high-speed steel (HSS) and tungsten carbide-tipped (TCT). HSS is the more affordable option, but it’s only suitable for cutting softer metals like copper and aluminum. If you need to make holes in cast iron or high-strength steel, you’ll want a TCT bit. Unfortunately, these bits are more expensive and cannot be resharpened, so replacement is the only option.

The plug cutter drill bit is different, as it isn’t designed to make holes. Instead, it cuts wooden plugs that cover counterbored holes, concealing the screws or bolts used to join pieces of wood. 

To use this drill bit, you need a jig or a drill press, as using a pilot hole to guide the plug cutter bit would create a hole in the plug and make it harder to hide. Once you’ve reached the limit of the plug cutter bit, pull it off the wood and use a screwdriver as a lever to remove the plug from its base. Then, dip it in wood glue, align the plug grain with the rest of the wood, and gently hammer the plug into the hole that you want to hide.

While you can use wood filler to hide holes, it would still leave obvious marks, especially if you plan to stain your woodworking project. To conceal it more naturally, you can use a plug cutter drill bit to create plugs with the same wood — or from a contrasting wood for a more striking design.