Made of high-quality steel. Can be used for shaping, hollowing most metals, plastics, and wood. No. 100: Shank Diameter: 1/8", Bit Diameter: 1/4", Material: High Speed Steel No. 114: Shank Diameter: 1/8", Bit Diameter: 5/16", Material: High Speed Steel No. 115: Shank Diameter: 1/8", Bit Diameter: 5/16", Material: High Speed Steel No. 116: Shank Diameter: 1/8", Bit Diameter: 1/4", Material: High Speed Steel No. 117: Shank Diameter: 1/8", Bit Diameter: 1/4", Material: High Speed Steel No. 118: Shank Diameter: 1/8", Bit Diameter: 1/8", Material: High Speed Steel No. 121: Shank Diameter: 1/8", Bit Diameter: 1/4", Material: High Speed Steel No. 124: Shank Diameter: 1/8", Bit Diameter: 5/16", Material: High Speed Steel No. 125: Shank Diameter: 1/8", Bit Diameter: 1/4", Material: High Speed Steel No. 134: Shank Diameter: 1/8", Bit Diameter: 1/4", Material: High Speed Steel No. 144: Shank Diameter: 1/8", Bit Diameter: 5/16", Material: High Speed Steel No. 190: Shank Diameter: 1/8", Bit Diameter: 3/32", Material: High Speed Steel No. 191: Shank Diameter: 1/8", Bit Diameter: 1/8", Material: High Speed Steel No. 192: Shank Diameter: 1/8", Bit Diameter: 3/16", Material: High Speed Steel No. 193: Shank Diameter: 1/8", Bit Diameter: 5/64", Material: High Speed Steel No. 194: Shank Diameter: 1/8", Bit Diameter: 1/8", Material: High Speed Steel No. 196: Shank Diameter: 1/8", Bit Diameter: 7/32", Material: High Speed Steel No. 199: Shank Diameter: 1/8", Bit Diameter: 3/8", Material: High Speed Steel