General description Neilsen Step Drill HSS Steel Titanium Cone Bit is designed for precision cutting of holes in metal and various other materials. This versatile tool features multiple step sizes, making it ideal for a range of applications. Technical specifications Material: HSS Steel with Titanium coating Step sizes: 4mm, 6mm, 9mm, 12mm, 15mm, 18mm, 21mm, 24mm, 27mm, 30mm, 33mm, 36mm, 39mm, 42mm Maximum diameter: 42mm