... Gauge (Diameter)BWGInch mmTolerance(mm)3/8"10mm±1.00.7mm - 1452' - 1M27, 26, 25, 24, 231/2"13mm±1.50.7mm - 952' ... - 2M25, 24, 23, 22, 215/8"16mm±2.00.7mm - 702' - 2M27, 26, 25, 24, 23, 223/4"20mm±3 ... 21, 20, 191"25mm±3.00.9mm - 551' - 2M25, 24, 23, 22, 21, 20, 19, 181-1/4"31mm±4.00.9mm - 401' ... - 2M23, 22, 21, 20, 19, 181-1/2"40mm±5.01.0mm - 451 ...