The Wolfcraft 2576000 Countersink Tool Set is a 10mm countersink crafted from tool steel and designed for marking? wood, metal, and plastic surfaces. The 10mm countersink is suitable for most common drilling and is ideal for use on furniture, frames, shelves, doors, and more. The countersink features a self-centering design, a steel construction for greater stability, and a comfortable handle for easy use. The countersink also comes with a hex nut to make removal and replacement easier.