Thread Geometry- British Standard Fine (BSF)

All Dimensions in inches unless otherwise stated
 

BSF Thread Geometry

d1 - Minor thread diameter male

d2 - Minor Thread diameter female

d3 - Pitch diameter

d4 - Major diameter

 

Thread Major Diameter Thread Per Inch Pitch Diameter Minor Diameter Male Thread
3/16 0.1875 32 0.1675 0.1475
7/32 0.2187 28 0.1959 0.1730
1/4 0.2500 26 0.2254 0.2008
9/32 0.2812 26 0.2566 0.2320
5/16 0.3125 22 0.2834 0.2543
3/8 0.3750 20 0.3430 0.3110
7/16 0.4375 18 0.4019 0.3663
1/2 0.5000 16 0.4600 0.4200
9/16 0.5625 16 0.5225 0.4825
5/8 0.6250 14 0.5792 0.5334

 

Thread Major Diameter Thread Per Inch Pitch Diameter Minor Diameter Male Thread
11/16 0.6875 14 0.6417 0.5959
3/4 0.7500 12 0.6966 0.6431
13/16 0.8125 12 0.7591 0.7057
7/8 0.8750 11 0.8168 0.7586
1 1.0000 10 0.9360 0.8720
1 1/8 1.1250 9 1.0539 0.9828
1 1/4 1.2500 9 1.1789 1.1078
1 3/8 1.3750 8 1.2950 1.2150
1 1/2 1.5000 8 1.4200 1.3400
1 5/8 1.6250 8 1.5450 1.4650

 

Thread Major Diameter Thread Per Inch Pitch Diameter Minor Diameter Male Thread
1 3/4 1.7500 7 1.6585 1.5670
2 2.0000 7 1.9085 1.8170
2 1/4 2.2500 6 2.1433 2.0366
2 1/2 2.5000 6 2.3933 2.2866
2 3/4 2.7500 6 2.6433 2.5366
3 3.0000 5 2.8719 2.7438
3 1/4 3.2500 5 3.1219 2.9938
3 1/2 3.5000 4 1/2 3.3577 3.2154
3 3/4 3.7500 4 1/2 3.6077 3.4654
4 4.0000 4 1/2 3.8577 3.7154
4 1/4 4.2500 4 4.0900 3.9300


Note: Due to the fact that fastening applications differ greatly, the above information is for guidance only and is correct to the best of our knowledge. The customer must satisfy themselves with the performance of the fastener and validity of the data. TR Fastenings will not be held responsible for any failure that may occur from the use of this information.