High Quality MaterialsClassic high speed steel, titanium coating on the surface, proven performance and durability in drilling holes in plastics, wood, aluminum, copper, stainless steel and many other types of sheet metal. Titanium alloy drill bits are especially suitable for processing copper and aluminum parts / die steel / spring steel / cast iron parts / iron and other metal materials Easy to drill The design of the two-slot spiral groove prevents slipping, quickly removes splinters and deburrs the hole, the pressure is low, drilling and cutting are faster and smoother; it can achieve faster, more stable and smoother cutting. The hole can be chamfered automatically to clean the drill bit Double cutting blades and three shanksDouble cutting blades and X-type opening design ensure faster and smoother cutting; 3-sided shank design can prevent the drill chuck from slipping; With the smallest pressure, the sets can cut through wood, sheet metal, steel and other surfaces UsesSuitable for home DIY and general building supervision. Widely used for cutting various materials such as wood, plastic, thin iron plate, thin aluminum plate and so on. It is suitable for workpieces with hardness less than 25, such as carbon steel, with plate thickness less than 5mm Save timeCovering assorted pitch sizes helps to drill or enlarge different holes in a bit without constantly changing bits. The size is laser etched into the metal, so it can be drilled precisely and will not wear off even if used for a long time Product Description Features: Top quality. This Step Drill Kit replaces 50 individual drill bits. The two-strand design allows for faster and more even cutting. The triangular shank (TRI-FLAT) does not slip in the chuck. Cobalt coated for a smoother, cooler cut, titanium coated to reduce friction and run cooler. The large drill bit has a 3-sided shank and the small drill bits have a hex shank to prevent the chuck from slipping. Automatic hole deburring while drilling. Quick work steel and durable. Padded aluminum protective case included Sizes: #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") Scope of delivery : 1 x 1/413/8 Step Drill 1 x 3/16-7/8 Step Drill 1 x 1/ 43/4 Step Drill 1 x 1 / 8 / 1 / 2 Step Drill 1 x 3 / 16 - 1 / 2 x Step Drill 1 aluminum box.