Alvord Polk 651-0 High-Speed Steel Repairman's Reamer, Straight Flute, Brace Shank, Uncoated Finish, 1/8 Inch Point Diameter, 1/2 Inch Large End Diameter Straight flute reamers are recommended for general purpose reaming to make minor enlargements to existing holes with a very precise size and roundness Straight flute reamers are good for use in through or blind holes without interruptions such as keyways (through holes extend through the entire workpiece, while blind holes do not) Brace shank tools have a tapered square profile, which most toolholders can grasp efficiently and without slipping as much as round shanks Uncoated (bright) tools have no finish or coating. They are a good choice for general purpose applications High-speed steel is a common general purpose steel for cutting tools, is compatible with a variety of materials, and tends to be lower in price than cobalt steel or carbide