Everything you need to know about metric drills and boring tools.

We get asked all the time by custom cabinet shops, closet makers and other small woodworking professionals to explain the best applications for brad point, thru bore or hinge boring bits. For many craftsmen, they’re accustomed to dealing with tools built using the U.S. standard form of measurement – not the metric system.

Since most of the major woodworking equipment manufacturers got their start in Europe, many of the industrial woodworking tools were manufactured to metric specifications (as this is the common standard of measurement throughout much of the world). For professionals just getting started with European-made machinery, we’re giving a high-level overview below of the three main types of drills and boring tools that they’re likely to encounter, including their best application.

Brad Point (or Dowel) Boring Bits

• Brad Point drills provide a clean entry and flat bottom hole in laminated composite wood and solid wood materials.  Brad Point drills will likely “blow out” the exit hole in most materials; however, when supported by a spoil board an acceptable exit hole may be obtained in some materials.

• Brad Point drills are typically used to provide a flat bottom drill hole for dowels, shelve pins and fasteners.

• Drills utilize the industry standard 10mm diameter shank with set screw flat.  The shank is internally threaded and holds a set screw for depth of cut adjustments or the set screw can be removed to use quick change connectors.

These drills typically come with a tungsten carbide tip (TCT) braised onto a steel shank, but many high-volume custom cabinet and closet makers choose the longer-lasting solid carbide style. ToolWolf offers both.

Thru-Bore (or V-tip) Boring Bits

• Thru-bore drills provide a clean entry and exit hole in laminated composite wood and solid wood materials.  They are designed to avoid “blow out” from the exit hole in most materials.

• Thru-bore drills are typically used to provide a clean drill hole for connections and fasteners.

• Drills utilize the industry standard 10mm diameter shank with set screw flat.  The shank is internally threaded and holds a set screw for depth of cut adjustments or the set screw can be removed to use quick change connectors.

These drills typically come with a tungsten carbide tip (TCT) braised onto a steel shank, but many high-volume custom cabinet and closet makers choose the longer-lasting solid carbide style. ToolWolf offers both.

Hinge (or Forstner-style) Boring Bits

• Hinge bit drills have a centering point and two carbide spur cutters to provide a clean entry and exit hole in single or double-sided laminated composite and solid wood materials.

• Hinge bit drills are used to provide drill holes for hinge, lock and door assemblies.

• Drills utilize the industry standard 10mm diameter shank with set screw flat.  The shank is internally threaded and holds a set screw for depth of cut adjustments or the set screw can be removed to use quick change connectors.

• Hinge bit drills are available in custom diameters and designs.  Solid carbide insert knife versions are available and provides for lower operating costs in high volume production applications.

These drills come with a tungsten carbide tip (TCT) braised onto a steel shank and head.

There you have it. A beginner’s guide to metric boring bits. If anyone out there has additional questions, please reach out to our team at ToolWolf and we’ll be happy to provide answers.