Alvord Polk 101-2 High-Speed Steel Hand Reamer, Left Hand Spiral Flute, Right Hand Cut, Uncoated Finish, Size: 1/2 Inch Left-hand spiral reamers are good for use in through holes (holes that extend all the way through a workpiece), as they push chips ahead of the tool and into the hole Spiral reamers are recommended for reaming holes with interruptions, as they prevent damage to the workpiece edge and tool Hand reamers fit into a tap wrench, adjustable hand wrench, or standard tap/reamer chucks 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