55° Whitworth Thread Gauge

Range: 4-42 TPI
Gradations: 4, 4-1/2, 5, 5-1/2, 6, 7, 8, 9, 10, 11,11-1/2, 12, 13, 14, 15, 16, 18, 19, 20, 22, 24, 26, 27, 28, 30, 32, 34, 36, 38, 40, 42 TPI