Tungsten Carbide Rotary burs 1, superior K20,K25, K30 quality 2, CNC machining 3, competitive factory price The Rotary carbide files more information as follow: TypeNo.Ød1mmØd2mml1mml2mmaSN-41M2.5338310° SN-42M333410°SN-53M53386.310°SN-1M6650810°SN-51M6.3344610°SN-2M9.56539.513°SN-4M12.765712.728°SN-6M166631918°SN-7M196601630°. Tungsten Carbide Rotary Burs