[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, thus saving time and money. [Premium Materials]: These step drills are made of heat-treated 4241 high speed steel (HSS) and coated with titanium nitride. 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 during drilling. Faster and smoother cut. Three flat handles provide a firm grip. Triangular round shank: Can be easily installed in electric screwdriver, drill bit and drill press. [Applies To]: The step drill set can be used for workpieces with hardness less than 25 and thickness less than 5mm. Suitable for various materials, such as carbon steel, sheet iron, insulation board, PVC board, wood panel and wood, etc. They also help to enlarge existing holes and are not recommended for stainless steel. Color: Gold Features: Color: Gold Material: High speed steel 4241 Surface: Titanium plated Rod type: Triangular round handle Shank size: 23 x 12 mm Size: 5-35mm (5, 7, 10, 12, 15, 17, 20, 22, 25, 27, 30, 32, 35mm) Use: For 5 mm thick material For metal sheets: Step drills are preferably used on thin materials, which corresponds to the thickness of the sheet. Sheet metal work also requires a number of different sized holes, which means workers should constantly change their drills. Since the step drill bit can adjust to a number of different sizes, you will save time using these drills for sheet metal work. For countersinking: Another purpose of step drills is to use them as countersinks. Since they are so versatile, they work great for securing screws and fasteners below a surface. When you drill holes in the opposite side of the materials, the small end can be used for this 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 in auto repair projects. Most body shops use many multi-stage drill bits for car restoration projects, which makes it time-consuming and costly. However, with step drills, they can use just one bit and save time with fewer bits required. Tips: 1. In order to prevent debris from damaging the eyes, please take protective measures when using. 2. As measurements are taken by hand, the sizes shown may vary from 0 to 3mm, which is completely normal. 3. Due to lighting effects or adjustments to the brightness or contrast of your screen, slight variations in color may appear between the photo on the site and the item itself. Package contents: 1 stepped drill bit from 5 to 35 mm (Gold)