FeelGlad&reg; 1/4"-1-3/8" High Speed Steel Titanium Step Drill Bit (Yellow) 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 Two flute design for smoother cutting 135 split point tip increases cutting speed with self-centering and prevents walking Step Sizes: 1/4", 3/8", 1/2", 5/8", 3/4", 7/8", 1", 1-1/8", 1-1/4", 1-3/8" Single-flute cutting edge for greater control through steps.