TDC® Greenfield® Chicago-Latrobe® Screw Extractor, Size: #4, List Number: 800, 3/16" Small End Diameter, Large End Diameter: 5/16", 3" Overall Length, 1" Flute Length, Screw/Stud Size: 7/16 to 9/16", Drill Size: 1/4", 1/8" Pipe Size, Material: Alloy Steel, Finish: Bright, Applicable Materials: Alloy Steel, Tool Steel, Low and Medium Carbon Steel, Cast Iron