Features Durable High-Speed Steel Construction: Crafted from high-speed steel and heat-treated for HRC48 to 50, ensuring long-lasting performance and resistance to wear during use Enhanced Efficiency with Tension Machine: Achieve double the drilling power when paired with the appropriate head and tension machine, making projects quicker and more efficient Versatile Woodworking Tool: Ideal for drilling into wood and compatible with a mill or morning coat, this tool is a must-have for woodworkers and DIY enthusiasts alike Labor-Saving Design: Significantly reduces the physical effort of construction work, speeding up processes in installation, renovation, and decoration while cutting costs Perfect Gift for Woodworkers: This practical set is an excellent gift option for woodworking enthusiasts, equipping them with essential tools for their craft Features: 1、This square hole drill bit is made of high？speed steel. With heat treatment, HRC48 to 50, high hardn, long hardn, and high concentration. 2、Use with the head and the tension machine will result in a double effect. Hole drilling requires the use of electric drills, hammers and other tools. 3、Suitable for drilling on wood, with a mill or a morning coat. Suitable for all motors and pr accories. The square？hole drill is mainly used for woodwork. 4、Reduce the labor strength of construction workers, accelerate the construction speed, and reduce the construction cost of construction, installation, renovation and decoration industries. 5、These square hole drill bit are tool for woodworkers, and you give these tools as gift to others. Specification: Item Type: Square Hole Drill Bit Material: Bearing Steel Diameter Specification: 6.35mm(1/4") 8mm(2/5" ) 9.5mm(3/8") 12.7mm(1/2") Purpose: Drilling Applicable Scene: for Woodworking Package List: 4 x Square Hole Drill Bit 4 x Drill Bushing 4 x Cap Package List 4 x Square Hole Drill Bit 4 x Drill Bushing 4 x Cap