The steel spiral bit set features an innovative flute design leading to faster material removal for easier drilling. It offers a speeds tip which penetrates material quickly. Commonly used for tap con installation, and brick block fastening. Features - Color: Assorted color. - Material: Steel. - Size: 9.00 x 2.00 x 1.80cm/ 3.54 x 0.79 x 0.71 inch. - Made from steel, durable, practical and . - Perfect for home DIY and general building engineering use. Easy for store and carry. - Fast drilling , flats allows drill bit to be held tightly and stably in power drill. - The surface of the drill bit is treated by fine polishing, and the new electroplating process can prevent the drill bit from rusting and prolong the life of the drill bit. - Cutter head resistance is smaller. And it can improve work efficiency, higher hardness than ordinary drill bit, more wear-resistant. Package list: 1 x counterbore drill (2.8 ) 1 x counterbore drill (2.8 x 10) 1 x counterbore drill (3 ) 1 x counterbore drill (3 x 10) 1 x counterbore drill (3.2 ) 1 x counterbore drill (3.2 x 10)