Nizzco Titanium Step Drill Bit Set,3-Piece Set High Speed Steel Bit,1/4-3/4,1/8-1/2,3/16-1/2,Total 28 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 . Hex Shank:fits into power tools chuck securely and eliminates slip . 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 . Total 28 Sizes: #1 (9 steps): 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4" ; #2 (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"; #3 (6 steps): 3/16", 1/4", 5/16", 3/8", 7/16", 1/2".