
【steel material and durable】This drill is made of special steel, heat treated, HRC48-50, offers high hardness, elongated core and high concentricity. 【Use】: It achieves a double effect when used with a mortise and tenon machine. An electric drill, hammer and other tools are required to punch square holes. 【6 different sizes】: 6 pieces per pack with different slot diameters to meet your needs. Size: 1/4 in (6.35 mm), 5/16 in (8 mm), 3/8 in (9.5 mm), 1/2 in (12.7 mm), 9/16 in (14 mm), 5/8 in (16 mm). 【Wide application】: The professional drill is suitable for construction, installation, renovation, decoration, etc. A great accessory for mortising, chiselling and woodworking.