General description This set of 3 countersink drill bits is crafted from high-quality M42 high-speed steel and features a titanium coating to minimize friction and heat during use. The unique step design allows for drilling holes of various sizes, eliminating the need for multiple drill bits. It is ideal for drilling into a range of materials including steel, brass, wood, and plastic. Technical specifications Material: M42 high-speed steel Coating: Titanium Sizes: 4 mm, 12 mm, 20 mm, 32 mm Usage No pilot holes or pre-drilling required Automatically deburrs holes as you drill Best suited for thin metals, steel, aluminum, copper, brass, fiberglass, and PVC Easily identify sizes with contrasting, laser-etched markings inside the bit flute