RUKO CBN-Ground HSS Countersink Bits

This document describes RUKO countersink bits made from fully hardened HSS blanks with CBN grinding for sharper, more durable cutting edges and precise tolerances. It includes specifications for both metric 90° taper bits (for DIN 335 Type C fasteners) and inch 82° taper bits (for UNC/UNF fasteners), along with a 5-piece set and usage recommendations for various industrial materials.