General description M35 cobalt high-speed steel step drill bits offer superior quality and durability compared to standard HSS 4241 drill bits. The titanium coating enhances their longevity, ensuring they remain shiny and effective for years. These bits feature a hex shank for easy attachment and are designed for various materials, including steel, aluminum, wood, and plastic. Technical specifications Material: High-Speed Steel Co (HSS Co M35) Surface Treatment: Titanium Coated Hex Shank Diameter: 6.35mm (1/4") Size Range: 4-20mm (includes 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm) Number of Steps: 9 Installation Can be used with both hand drills and bench drills. For hand drilling, suitable for steel sheets up to 1mm thick. For bench drilling, can drill steel sheets of 2-3mm thickness. Usage Drill at low speeds when working with stainless steel sheets; hundreds of RPM is acceptable. Water cooling is recommended during punching to extend the drill's service life; a rotation