Neiko 10197A Titanium Step Drill Bit Set, High Speed Steel | 5-Piece Set | Total 50 Sizes Classic high speed steel with titanium coating for proven capability and durability in drilling holes in plastic, aluminum, copper, stainless steel and many other types of sheet metal 135 split point and two flute design increases cutting speed with self-centering and prevents walking, clears chips faster and allows particles to escape easily Tri flatted shank fits into power tools chuck securely and eliminates slip Set includes a sturdy blow molded organizing case for secure storage and easy carrying Set includes: Drill Bit #1 (10 step sizes): 1/4", 3/8", 1/2", 5/8", 3/4", 7/8", 1", 1-1/8", 1-1/4", 1-3/8; Drill Bit #2 (12 step sizes): 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 13/16", 7/8; Drill Bit #3 (9 steps): 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4"; Drill Bit #4 (13 steps): 1/8", 5/32", 3/16", 7/32", 1/4", 9/32", 5/16", 11/32", 3/8", 13/32", 7/16", 15/32", 1/2"; Drill Bit #5 (6 steps): 3/16", 1/4", 5/16", 3/8", 7/16", 1/2"