RUKO Drill Bits & Parts Metal twist drill bit 616444 - RUKO 259055E, The RUKO Metal Twist Drill Bit 259055E is a 5.50 mm diameter tool with a total length of 93 mm, featuring a triangular shank. Manufactured to DIN 338 standards, it is designed for precision drilling in metal, steel, and sheet metal applications. This high-quality drilling bit is ideal for use in a range of machining and construction tasks. RUKO 259055E HSSE-Co 5 Twist Drill Bit 5.50mm DIN 338 Triangular