Diamond Core Drill Bits with a 1 Connector Diameter 150 MM L 400 MM. Introducing our top-quality Diamond Core Drill Bits with a 1 Connector Diameter of 150 MM and a length of 400 MM. These drill bits are ideal for woodworking projects and are made from high-grade diamond material for superior durability and performance. Designed for use with a standard drill, our Core Drill Bits are perfect for creating precise and clean holes in wood. With a sturdy construction and a sharp diamond tip, these drill bits can easily penetrate through even the toughest of materials. So whether you’re a DIY enthusiast or a professional woodworker, our Diamond Core Drill Bits are just what you need to get the job done quickly and efficiently.