Union Butterfield 4500 High-Speed Steel Hand Reamer, Straight Flute, Round With Square End Shank, Uncoated (Bright), 1 inch Straight flute reamer for general purpose reaming to make minor enlargements to existing holes with a 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) Square end shank fits into a tap wrench, adjustable hand wrench, or standard chuck and helps prevent rotation in the tool holder High-speed steel is a common general-purpose steel for cutting tools and is compatible with a variety of materials Uncoated (bright) tools have no additional surface treatment or coating, suitable for general-purpose applications