5 Ingenious Drill Bits You Never Knew About

Many DIY enthusiasts typically turn to a standard drill bit set for creating small holes in wood, metal, and plastic. However, a range of specialized drill bits exists that can tackle a wider array of tasks and materials, provided you select the appropriate bit for your specific needs. Here, we highlight several distinctive drill bits that fulfill specialized roles.

While various bits might be focused on drilling holes, they often create larger openings than the usual points utilized for inserting tiny screws into wood and other materials. These bits can facilitate the construction of plug compartments or angled holes to enable the joining of materials at right angles.

Among the most effective methods for connecting wooden pieces is pocket hole joinery, which involves drilling at an angle to create a “pocket” for the screw. This technique keeps screws out of sight, whether concealed by drilling on the interior side or covering holes using wooden plugs.

For this, a pocket hole jig is recommended to ensure accuracy, especially when working with materials that may shift during drilling. Using a stepped drill bit is ideal for this task; it features a smaller tip for drilling the pilot hole before enlarging the hole to accommodate the screwhead with its larger diameter. This streamlined approach simplifies the process of making pocket holes and is particularly useful for those new to woodworking.

While it’s possible to create pocket holes without a specialized stepped bit, it demands the use of two different bits—one for the pilot hole and another for the pocket—leading to an increased risk of errors during drilling.

Standard drill bits excel at making small holes for screw insertion, but they fall short when larger fixtures are needed. If you are working on a cabinet or need to install a grommet in a wooden desk for wires, a Forstner bit is necessary for creating flat-bottomed holes, ideal for hinges or dowel joints, or for precise cuts in high-quality hardwood.

While a spade bit can produce holes similar to those made with a Forstner bit, it typically creates rough cuts, making it unsuitable for projects that require a smooth finish. A hole saw can create larger openings, but it simply cannot provide flat-bottomed holes required for specific applications.

A Forstner bit serves as a valuable addition to your toolkit, especially when working on custom cabinetry or other woodworking endeavors.

For cutting large holes in materials like concrete and brick, a coring drill bit is the tool of choice. This cylindrical, hollow bit features sharp teeth along its edge, but the depth of its drilling is limited by the cylinder’s length. When the bit has reached its maximum depth, the operator must remove it to extract the remaining core material before proceeding.

Commonly available in two varieties—carbide and diamond—carbide coring bits, which use tungsten carbide teeth, are usually the more cost-effective option. While adequate for masonry, they’re not particularly efficient when encountering materials like steel rebar. On the other hand, diamond coring bits can handle such materials while providing cleaner cuts; however, they require regular cooling intervals during use or a water-cooling system to remain effective.

For drilling large-diameter holes in metals, using a standard wood or masonry bit won’t suffice. Instead, an annular cutter drill bit is required. Though they may appear similar to hole saws or coring bits, those alternatives often lack the capability to cut through materials like aluminum or steel.

Renowned for their ability to produce clean, precise holes, annular cutter bits ensure that edges are smooth and do not require deburring or reaming, which saves considerable time and effort during project execution. Both high-speed steel (HSS) and tungsten carbide-tipped (TCT) are available, with HSS being the more economical option for softer metals. TCT bits, although more costly and non-resharpenable, are necessary for tougher materials like cast iron or high-strength steel.

A plug cutter drill bit is distinct in that it does not create holes; rather, it slices wooden plugs used to cover counterbored openings, effectively hiding screws or bolts that connect wood pieces.

To utilize this bit, a jig or a drill press is essential, as relying on a guide may accidentally create a hole in the plug, compromising its concealment potential. After reaching the desired depth with the plug cutter, remove it from the wood and use a screwdriver to extract the plug. Then, apply wood glue, align the grain with the adjoining wood, and gently tap the plug into place.

While wood filler can hide holes, it often leaves noticeable imperfections—especially under stains. A plug cutter drill bit enables you to create matching or contrasting plugs from the same wood to achieve a more seamless and visually appealing finish.