This is a brand new 3-piece hinge drill bit set from Amtech. The set includes three assorted drill bit diameters made from high-speed steel, designed for precise hinge fittings. The drill bits have sizes of 1 x 2.8mm, 1 x 3.6mm, and 1 x 4.5mm. These HSS drills feature a hex recess shank and are suitable for drilling pilot holes in metal, plastic, wood, and more.