RUKO countersinks are now available in both 82° taper for UNC and UNF fasteners and DIN 335 Type C 90° taper for metric fasteners. RUKO countersinks are ground from fully hardened, High-Speed Steel (HSS) blanks with a sharper, more precise and more durable cutting edge for a smooth, low-heat, chatter-free cut that is up to 30% faster than competing countersink bits. These tough bits are suitable for all standard industrial materials: steel, cast iron, stainless steel, non-ferrous metal, thermoplastics, and duroplastics. Eight 82-degree countersink bits are available in diameters from 1/4 to 1-inch, and five 90-degree countersink bits are available in sizes from 10.4mm to 25mm. 5-piece 82-degree and 90-degree countersink sets are also available. Individual countersink bits start at $10.00 and the 5-piece countersink bit sets start at $85.00.