476 Screw Pitch Gauge tpi 3 1/2 - 60
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. Whitworth standard - 55 threads No. of leaves: 30 TPI range: 3 1/2 - 60 With positive stop.