Reamers are a cutting tool used on drilled holes to refine them into the required hole-diameter precision and surface roughness while shaping them into true circles. Reamers are selected according to the precision of the hole as needed. They vary in hardness and size from the ones used to cut holes in parts of aircrafts to those used to manufacture musical instruments. Different reamers are selected based on their applications; hand reamers used for manual operation with handles attached to them, chucking reamers mounted to drill presses or NC machine tools for machining, machine reamers with longer cutter section than that of chucking reamers, taper reamers for finishing tapered drilled holes, bridge reamers used for correcting bolt holes, etc., when there is misalignment in them, and more. Their materials include high-speed steel or coated high-speed steel, carbide or coated carbide; reamer types vary according to the material of the parts for machining, machining method (manual or machine tool) and the cutting fluid types.