Starrett STR6 6 Screw Pitch Gauge 4-42 TPI Screw pitch gauges quickly determine the pitch of various external and internal threads. These gauges consist of a substantial steel case with a number of folding leaves at both ends, each leaf having teeth corresponding to a definite pitch. American national - 60 degree; threads No. of leaves: 30 TPI range: 4 - 42 Locking device.
