Premium Material: These step drill sets are made of exceptionally strong HSS steel and coated with titanium, making them wear-resistant, corrosion-resistant, rust-resistant, robust, and durable. Quick Attachment: The 1/4" (6.35 mm) hex shank works with most drill bits or drills with a 1/4" chuck. The double-edged design allows for faster and more consistent drilling at low pressure. Easy to Use: The metal step drill bit fits securely into the drill chuck of power tools and prevents slippage. The tapered step drill bit allows for precise drilling of holes of various sizes, with optimal speed and accuracy. Widely Used: The titanium drill bit is suitable for machining copper and aluminum parts, cast steel, spring steel, cast iron, iron, and other metal materials. Widely used for drilling holes in aluminum, insulation panels, PVC panels, and wood up to 5 mm thick.