TurningMillingDrillingTechnicalInformationIndex Threading System overview A Thread types Profile Sectional drawing Insert Internal threadpitch [mm]External threadpitch [mm]Page ISO metric coarse thread 60°full profileGM 0,5-6,0 0,5-6,0 A413 60o B ISO metric coarse thread 60°partial profile60° 0,5-5,0 (5-48) 0,5-5,0 (5-48) A415 55o ISO metric coarse thread 55°partial profile55° 0,5-5,0 (5-48) 0,5-5,0 (5-48) A416 C Whitworth W 8-16 8-16 A417 UN unified conventionalthread 60° full profileUN 8-20 8-20 A418 D BSPT Whitworth taper pipethreadBSPT 11-28 11-28 A419 NPT American taper pipethread NPT 8-27 8-27 A420 1o47 E 30o 30o NPTF dryseal American taperpipe thread 60°NPTF 8-27 8-27 A421 90o 1o47’ A 406