Flank angle tolerances for metric threads

THREAD CUTTING & FORMING - Concordia University

Standards: Unified (American)-dim. in inches, pitch in Threads Per Inch (TPI)ISO (Metric)- dim. in mm or inches, pitch in mm Types: UNC/NC: Coarse Thread –Regular use not subjected to vibration /Series UNF/NF: Fine Thread –Automotive and Aircraft UNEF/NEF: Extra Fine Thread –Thin structures, High TPI. 8Thread Series, 8UN, 8N: 8TPI, Dia 1-6”.

  Thread, Metrics