Features 1、This square hole drill bit is made of high‑speed steel. With heat treatment, HRC48 to 50, high hardness, long hardness, 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 press accessories. 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 perfect 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