Neiko 10194A Titanium Step Drill Bit, High Speed Steel | 1/4" to 1-3/8" | Total 10 Step Sizes TITANIUM | HIGH SPEED STEEL: 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 TIP: increases cutting speed with self-centering and prevents walking TWO-FLUTE DESIGN: clears chips faster and allows particles to escape easily TRI-FLATTED SHANK: fits into power tools chuck securely and eliminates slip INCLUDES 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"