The sharpness and titanium coating ensures easily cut through most sheet metal,aluminum sheets, wood board, plastic board, and some other materials with ease.Non-walking drill tip provides fast and smooth drills on steel sheets, aluminum sheets, wood board, plastic board etc. (the board must be smaller in thickness than the height of step drill bits).Cobalt high speed steel along with the titanium coating ensures extreme durability, will stay new and shiny for years to come.Two-Flute Design and 3-sided shank design. 3-sided shank design prevents drill bits from slipping;2-flute design provides a faster and smoother cutting, and easy to read rings, 1.5 times faster than basic drill bits. Keep the drill bit clean.Replaces 50 individual drill bits in 5 pieces step drill bits, which saves you a lot of trouble and space.Two-fluted design provides faster and smoother cutting. Cobalt steel along with titanium coating ensures this set with outstanding.durability and will stay sharp for years to come, perfect to cut holes on steel, aluminum sheets etc. 1: 3/16" to 1/2" 6 Steps (3/16'', 1/4'', 5/16", 3/8'', 7/16'', 1/2'') 2: 1/8" to 1/2" 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: 1/4" to 3/4'' 9 Steps (1/4'', 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4") 4: 1/4" to 1-3/8" 10 Steps (1/4'', 3/8", 1/2", 5/8", 3/4", 7/8", 1", 1-1/8", 1-1/4", 1-3/8") 5: 3/16" to 7/8" 12 Steps (1/4'', 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 13/16", 7/8")"Package Include:5x Step Drill Bit Set