Rosca Whitworth paralela para tubos (BSP) Diámetro Filetes por pulgada pulgadas Nº/pulg Máximo Diámetro del Núcleo Mínimo Diámetro de la Broca mm 1/8" 28 8.848 6.673 8.70 1/4" 19 11.890 11.633 11.75 3/8" 19 15.395 15.138 15.25 1/2" 14 19.172 18.823 19.00 5/8" 14 21.128 20.779 20.00 3/4" 14 24.658 24.310 24.50 7/8" 14 28.418 29.069 28.20 1" 11 30.931 30.487 30.50 1 1/8 11 35.579 35.135 35.40 1 1/4 11 35.592 39.148 39.50 1 3/8 11 42.005 41.561 41.80 1 1/2 11 45.485 45.041 45.20 1 3/4 11 51.482 50.984 51.20 2" 11 57.296 56.852 57.00 2 1/2 11 72.866 72.422 72.70 2 3/4 11 79.216 78.772 79.00 3" 11 85.566 85.122 85.30