Features:_x000D_- This Item ia brand new_x000D_- This set replaces 50 individual drill bits. Two-flute layout gives you faster, smoother cutting. 3-sided (TRI-FLAT) shank will not slip in your drill's chuck. Cobalt coated for smoother cooler cutting_x000D_- Ti coated to reduce friction and run cooler_x000D_- Large bit has 3-sided shank and small bits have hex shank to prevent slip in drill chuck_x000D_- Automatically deburrs holes as you drill_x000D_- Long Life high speed steel_x000D_- Includes protective padded aluminum case_x000D_- Package Size:15cm*10.5cm*4.2cm(L*W*H)_x000D__x000D__x000D_Sizes:_x000D_#1: 3/16" to 1/2" 6 Steps (3/16'', 1/4'', 5/16", 3/8'', 7/16'', 1/2'')_x000D_#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'')_x000D_#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")_x000D_#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")_x000D_#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")_x000D__x000D__x000D_Package included:_x000D_1 x 1/4-1-3/8 Step Drill_x000D_1 x 3/16-7/8 Step Drill_x000D_1 x 1/4-3/4 Step Drill_x000D_1 x 1/8-1/2 Step Drill_x000D_1 x 3/16-1/2 Step Drill_x000D_1 x Aluminum Box 1Made of ti-coated high-speed steel, these hex shank step drill sets have high hardness. 2The step drill bit sets adopts groove design, help the electric drill clamp it more firmly, prevent sliding or falling off during rotation. 3It is very suitable for using to cut holes in a variety of materials including steel, brass, wood, plastic, etc. 4Cobalt coated for smoother cooler cutting, automatically deburrs holes as you drill. 5Using high?quality materials, strong and durable, has a long service life.