SWG Gauge inches mm 7/0 0.500 12.700 6/0 0.464 11.786 5/0 0.432 10.973 4/0 0.400 10.160 3/0 0.372 9.449 2/0 0.348 8.839 1/0 0.324 8.230 1 0.300 7.620 2 0.276 7.010 3 0.252 6.401 4 0.232 5.893 5 0.212 5.385 6 0.192 4.877 7 0.176 4.470 8 0.160 4.064 9 0.144 3.658 10 0.128 3.251 11 0.116 2.946 12 0.104 2.642 13 0.092 2.337 14 0.080 2.032 15 0.072 1.829 16 0.064 1.626 17 0.056 1.422 18 0.048 1.219 19 0.040 1.016 20 0.036 0.914 21 0.032 0.813 22 0.028 0.711 23 0.024 0.610 24 0.022 0.559 25 0.020 0.508 26 0.018 0.457 27 0.0164 0.417 28 0.0148 0.376 29 0.0136 0.345 30 0.0124 0.315 31 0.0116 0.295 32 0.0108 0.274 33 0.0100 0.254 34 0.0092 0.234 35 0.0084 0.213 36 0.0076 0.193 37 0.0068 0.173 38 0.006 0.152 39 0.0052 0.132 40 0.0048 0.122 41 0.0044 0.112 42 0.004…

Nominal Pipe Size (NPS) is a American standard sizes for pipes used for high or low pressure and temperature. Pipe size is specified with two non-dimensional numbers: a nominal pipe size (Nominal Pipe Size) based on inches, and a schedule (Sched. or Sch.). Nominal Pipe Size is often incorrectly called National Pipe Size, due to confusion with national pipe thread (NPT). The European designation equivalent to Nominal Pipe Size is DN (diamètre nominal/nominal diameter), in which sizes are measured in millimetres.The term NB (nominal bore) is also frequently used interchangeably with Nominal Pipe Size. According to ASME B36.10 and ASME B 36.19. Nominal Pipe Size 1/8 to Nominal Pipe Size 3½ Nominal Pipe Size DNmm ODinches (mm) WTinches (mm) WTinches (mm) WTinches (mm) WTinches (mm) WTinches (mm) WTinches (mm) WTinches (mm) WTinches (mm) — — — SCH 5 SCH 10 SCH 30 SCH 40/STD SCH 80 SCH 120 SCH 160 XXS ⅛ 6…