PCB drill bits are used with power tools to remove material and create holes. PCB drill bits come in many sizes and shapes and can create different kinds of holes in many different materials. Why getting the right drill bit is important Soft materials can usually be drilled safely with almost any bit. However, hard or brittle materials like glass and acrylic require specially designed PCB drill bits to produce accurate, clean holes. This is especially important when it comes to drilling holes in printed circuit boards because they’re made of highly abrasive fibreglass. How to use your PCB drill bit to make the perfect hole Virtually all PCB drill bits are designed to spin clockwise. While this isn’t a problem on a drill press, many hand drivers are reversible; if your drill bit is spinning but not cutting, make sure it’s going in the right direction. Before you start drilling be sure to fully tighten the bit in the drill. Then you can let the tool do most of the work and simply apply some steady pressure.