British Standard Fine Threads Chart

British Standard Fine Threads Chart

THREAD DATA CHART
British Thread (British Standard Fine) -- Fine Pitch
Nominal Size BSF Thread Form Type Major Diameter mm d=D Pitch mm p Threads per inch tpi Pitch Diameter mm d2=D2 Minor Diameter Male Thd. d3 Thread Height H1 Tap Drill Diameter mm
3/16" BSF 4.763 0.794 32 4.255 3.747 0.508 4.00
7/32" BSF 5.556 0.907 28 4.975 4.394 0.581 4.60
1/4" BSF 6.350 0.977 26 5.725 5.100 0.625 5.30
9/32" BSF 7.142 0.977 26 6.518 5.893 0.625 6.10
5/16" BSF 7.938 1.156 22 7.199 6.459 0.739 6.80
3/8" BSF 9.525 1.27 20 8.712 7.899 0.813 8.30
7/16" BSF 11.113 1.411 18 10.209 9.304 0.904 9.70
1/2" BSF 12.700 1.588 16 11.684 10.668 1.017 11.10
9/16" BSF 14.288 1.588 16 13.272 12.256 1.017 12.70
5/8" BSF 15.875 1.814 14 14.712 13.549 1.162 14.00
11/16" BSF 17.463 1.814 14 16.300 15.137 1.162 15.50
3/4" BSF 19.050 2.117 12 17.693 16.336 1.355 16.75
13/16" BSF 20.638 2.117 12 19.281 17.924 1.355 18.25
7/8" BSF 22.225 2.309 11 20.747 19.269 1.479 19.75
1" BSF 25.400 2.54 10 23.774 22.148 1.627 22.75
1-1/8" BSF 28.575 2.822 9 26.769 24.963 1.807 26.50
1-1/4" BSF 31.750 2.822 9 29.944 28.138 1.807 28.75
1-3/8" BSF 34.925 3.175 8 32.893 30.861 2.033 31.50
1-1/2" BSF 38.100 3.175 8 36.068 34.036 2.033 34.50
1-5/8" BSF 41.275 3.175 8 39.243 37.211 2.033 38.00
1-3/4" BSF 44.450 3.629 7 42.126 39.802 2.324 40.50
2" BSF 50.800 3.629 7 48.476 46.152 2.324 47.00
2-1/4" BSF 57.150 4.234 6 54.440 51.730 2.711 53.00
2-1/2" BSF 63.500 4.234 6 60.790 58.080 2.711 59.00
2-3/4" BSF 69.850 4.234 6 67.140 64.430 2.711 n/a
3" BSF 76.200 5.08 5 72.946 69.692 3.253 n/a
3-1/4" BSF 82.550 5.08 5 79.296 76.042 3.253 n/a
3-1/2" BSF 88.900 5.645 4 1/2 85.285 81.670 3.614 n/a
3-3/4" BSF 95.250 5.645 4 1/2 91.635 88.020 3.614 n/a
4" BSF 101.600 5.645 4 1/2 97.985 94.370 3.614 n/a
4-1/4" BSF 107.950 6.35 4 103.886 99.822 4.066 n/a