[Step Drill Size]: 5-35mm(5mm , 7mm ,10mm ,12mm ,15mm ,17mm ,20mm ,22mm ,25mm ,27mm ,30mm ,32mm ,35mm). A variety of drill bits can meet your different needs, saving time and money. [Premium Materials]: These step drill bits are made of heat treated 4241 high speed steel (HSS) and titanium nitride coated. The titanium coating can reduce friction and operating temperature, which can effectively extend the service life. [Ladder structure]: The drill bit can drill holes of different specifications without purchasing multiple drill bits, saving space and money. [Double Groove]: Automatic deburring when drilling. Faster and smoother cutting. Three flat handles ensure a firm grip. Triangular round shank: can be easily installed in electric screwdriver, drill bit and pressure drill. thickness less than 5 mm. Suitable for various materials, such as carbon steel, iron sheet, insulation board, PVC board, wooden board and wood, etc. They also help to enlarge existing holes and are not recommended for stainless steel. Features: Color: Silver. Material: 4241 High Speed Steel. Shank Type: Triangular Round Handle . Size: 5-35mm (5,7,10,12,15,17,20,22,25,27,30,32,35mm). Usage: 5 mm material thickness. For sheet metal: Stepped drill bits are best used on thin materials, which is the description of the sheet metal. Sheet metal work also requires a number of different sized holes, which means workers would constantly have to change their drill bits. Since the single-step drill bit can change to a number of different sizes, you'll save time using these bits for sheet metal work. For countersinks: Another purpose of step drill bits is to use as milling cutters. Since they are so versatile, they work great for securing screws and fasteners below a surface. When drilling holes in the opposite side of materials, small bits are great for doing that job. This is a good technique when reinforcing bolts and other fasteners, as well as adding stability to various construction projects. For auto repair: Another great use for step drills is on automotive repair projects. Most body shops use a lot of multi-stage bits for car restoration projects, making it an expensive and time-consuming job. However, with stepped drill bits, they can stick with just one drill bit and save time with fewer drill bits needed. Tips: 1. In order to prevent debris from damaging the eyes, please take protective measures when using. Due to hand measurement, sizes shown may vary by 0-3mm, which is This is completely normal. Due to lighting effects or monitor's brightness or contrast settings, there may be slight color variations between the website photo and the actual item itself. Package Contents: 1 x 5-35mm Step Drill Bit (Silver).