General description The FLITI HSS Metal Step Countersink Drill Bit set includes 4 pieces of high-quality HSS steel drill bits with a titanium coating, designed for drilling holes of various sizes in multiple materials such as steel, wood, brass, plastic, and PVC. This versatile set is ideal for both home use and construction projects. Technical specifications Sizes: 4-12mm, 4-20mm, 4-32mm Length: 1*65mm, 1*75mm, 1*100mm Material: High-speed steel (HSS) with titanium coating Compatibility and accessories Includes 1 centering punch made of impact-resistant alloy steel for easy positioning before drilling Usage Suitable for drilling holes in steel, brass, wood, plastic, thin iron plates, aluminum materials, insulation boards, and PVC boards Positioning and pre-drilling to protect the cone drill