7 ME Screw Threads 32-40 TPI ME Screw Threads 32-40 TPI in 55 1 0.1250 ME 1/8-40 ME 1/8-40 40 external B 0.1213 0.1057 0.0902 internal A 0.1250 0.1090 0.0930 0.0938 0.1562 ME 5/32-40 ME 5/32-40 40 external B 0.1515 0.1365 0.1214 internal A 0.1562 0.1407 0.1252 0.1285 0.1875 ME 3/16-40 ME 3/16-40 40 external B 0.1819 0.1664 0.1508 internal A 0.1875 0.1715 0.1555 0.1570 0.2188 ME 7/32-40 ME 7/32-40 40 external B 0.2122 0.1967 0.1812 internal A 0.2188 0.2028 0.11868 0.1890 0.2500 ME 1/4-40 ME 1/4-40 40 external B 0.2425 0.2270 0.2115 internal A 0.2500 0.2340 0.2180 0.2210 ME 1/4-32 ME 1/4-32 32 external B 0.2400 0.2231 0.2037 internal A 0.2500 0.2300 0.2100 0.2130 0.2812 ME 9/32-40 ME 9/32-40 40 external B 0.2728 0.2572 0.2417 internal A 0.2812 0.2652 0.2492 0.257 ME 9/32-32 ME 9/32-32 32 external B 0.2700 0.2534 0.2340 internal A 0.2812 0.2612 0.2412 0.246 0.3125 ME 5/16-40 ME 5/16-40 40 external B 0.3031 0.2876 0.2721 internal A 0.3125 0.2965 0.2805 0.290 ME 5/16-32 ME 5/16-32 32 external B 0.3031 0.2837 0.2643 internal A 0.3125 0.2925 0.2725 0.277 0.375 ME 3/8-40 ME 3/8-40 40 external B 0.3638 0.3482 0.3327 internal A 0.3750 0.3590 0.3430 0.348 ME 3/8-32 ME 3/8-32 32 external B 0.3638 0.3444 0.3250 internal A 0.375 0.355 0.335 0.339 0.4375 ME 7/16-40 ME 7/16-40 40 external B 0.4244 0.4089 0.3933 internal A 0.4375 0.4215 0.4055 0.413 ME 7/16-40 ME 7/16-40 32 external B 0.4200 0.4050 0.3856 internal A 0.4375 0.4175 0.3975 0.404 0.500 ME 1/2-40 ME 1/2-40 40 external B 0.485 0.4695 0.454 internal A 0.5 0.4840 0.468 0.4688 ME 1/2-32 ME 1/2-32 32 external B 0.4800 0.4656 0.4462 internal A 0.500 0.480 0.460 0.4688