Shank Styles A Shank 3mm solid carbide shank B Shank 3mm hardened steel shank C Shank 6mm hardened steel shank D Shank 3mm solid carbide shank Bur Cutting Speeds Bur Diameter Recommended Cutting Speed (RPM) Maximum Cutting Speed (RPM) 1,6mm 60,000–90,000 100,000 3,0mm 40,000–70,000 90,000 4,8mm 35,000–60,000 80,000 6,4mm 30,000–50,000 70,000 8,0mm 20,000–40,000 68,000 9,5mm 20,000–40,000 66,000 11,1mm 15,000–40,000 58,000 12,7mm 15,000–40,000 50,000 15,9mm 12,000–25,000 40,000 19,1mm 10,000–20,000 33,000 25,4mm 7,500–20,000 25,000 28,8mm 7,000–13,000 20,000 38,1mm 5,000–10,000 17,000 44,5mm 4,500–9,000 14,000 50,8mm 4,000–8,000 12,500 widia.com R5