Insize Thread Pitch Gauge. Pitch of leaves Included (TPI) : 4 TPI, 4-1/2 TPI, 5 TPI, 5-1/2 TPI, 6 TPI, 7 TPI, 8 TPI, 9 TPI, 10 TPI, 11 TPI, 11-1/2 TPI, 12 TPI, 13 TPI, 14 TPI, 15 TPI, 16 TPI, 18 TPI, 20 TPI, 22 TPI, 24 TPI, 26 TPI, 27 TPI, 28 TPI, 30 TPI, 32 TPI, 34 TPI, 36 TPI, 38 TPI, 40 TPI, 42 TPI.