Thread Geometry- British Association (BA)

All Dimensions in inches unless otherwise stated
 

BA Thread Geometry

d1 - Minor thread diameter male

d2 - Minor Thread diameter female

d3 - Pitch diameter

d4 - Major diameter

 

Thread Major Diameter Threads Per Inch Pitch Diameter Minor Diameter Male Thread
No. 16 0.03110 134 0.02630 0.02205
No. 15 0.03543 121 0.03016 0.02559
No. 14 0.03937 110 0.03358 0.02835
No. 13 0.04724 102 0.04094 0.03543
No. 12 0.05118 91 0.04413 0.03780
No. 11 0.05906 82 0.05122 0.04449
No. 10 0.06693 73 0.05811 0.05039
No. 9 0.07480 65 0.06496 0.05630
No. 8 0.08661 59 0.07579 0.06614
No. 7 0.09843 53 0.08634 0.07559

 

Thread Major Diameter Threads Per Inch Pitch Diameter Minor Diameter Male Thread
No. 6 0.11024 48 0.09689 0.08504
No. 5 0.12598 43 0.11110 0.09803
No. 4 0.14173 38 0.12508 0.11063
No. 3 0.16142 35 0.14303 0.12677
No. 2 0.18504 31 0.16461 0.14685
No. 1 0.20866 28 0.18598 0.16614
No. 0 0.23622 25 0.21102 0.18898


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.