BSW thread called British Standard Whitworth，It is the imperial unit screw thread standard established in 1841 by Joseph Whitworth and earlyest national thread standard in the world.It is from UK and adobed by many countrys fast.
Rounded crests and roots, designed for high strength.
diameter in inch -"Threads Per Inch" (TPI) for pitch
such as 1/2”-12 means diameter is 1/2” and TPI is 12
British Standard Fine (BSF)
British Standard Pipe (BSP)
British Standard Conduit (BSCon)
British Standard Copper (BSCopper) threads
|
Thread |
Tolerance |
Use For
|
|
internal thread (nut) |
medium |
High-quality general threaded parts |
|
normal |
High-quality general fasteners | |
|
external thread (bolt) |
close |
There are extremely high precision requirements for pitch and tooth profile, and it is necessary to achieve good tight fit. |
|
medium |
High-quality general fasteners |
|
|
free |
Large quantities of manufactured threaded fasteners |
|
Dia
in.
|
TPI
|
Pitch
inch
|
Thread Height
inch
|
Major diameter
inch
|
Pitch diameter
inch
|
Minor diameter
inch
|
Area of base of the tooth
inch2
|
| 1/8 | 40 | 0.02500 | 0.0160 | 0.1250 | 0.1090 | 0.0930 | 0.0068 |
| 3/16 | 24 | 0.04167 | 0.0267 | 0.1875 | 0.1608 | 0.1341 | 0.0141 |
| 1/2 | 20 | 0.05000 | 0.0320 | 0.2500 | 0.2180 | 0.1860 | 0.0272 |
| 5/16 | 18 | 0.05556 | 0.0356 | 0.3125 | 0.2769 | 0.2413 | 0.0457 |
| 3/8 | 16 | 0.06250 | 0.0400 | 0.3750 | 0.3350 | 0.2950 | 0.0683 |
| 7/16 | 14 | 0.07143 | 0.0457 | 0.4375 | 0.3918 | 0.3461 | 0.0941 |
| 1/2 | 12 | 0.08333 | 0.0534 | 0.5000 | 0.4466 | 0.3932 | 0.1214 |
| 9/16 | 12 | 0.08333 | 0.0534 | 0.5625 | 0.5091 | 0.4557 | 0.1631 |
| 5/8 | 11 | 0.09091 | 0.0582 | 0.6250 | 0.5668 | 0.5086 | 0.2032 |
| 11/16 | 11 | 0.09091 | 0.0582 | 0.6875 | 0.6293 | 0.5711 | 0.2562 |
| 3/4 | 10 | 0.10000 | 0.0640 | 0.7500 | 0.6860 | 0.6220 | 0.3039 |
| 7/8 | 9 | 0.11111 | 0.0711 | 0.8750 | 0.8039 | 0.7328 | 0.4218 |
| 1 | 8 | 0.12500 | 0.0800 | 1.0000 | 0.9200 | 0.8400 | 0.5542 |
| 1-1/8 | 7 | 0.14286 | 0.0915 | 1.1250 | 1.0335 | 0.9420 | 0.6969 |
| 1-1/4 | 7 | 0.14286 | 0.0915 | 1.2500 | 1.1585 | 1.0670 | 0.8942 |
| 1-1/2 | 6 | 0.16667 | 0.1067 | 1.5000 | 1.3933 | 1.2866 | 1.3000 |
| 1-3/4 | 5 | 0.20000 | 0.1281 | 1.7500 | 1.6219 | 1.4938 | 1.7530 |
| 2 | 4.5 | 0.22222 | 0.1423 | 2.0000 | 1.8577 | 1.7154 | 2.3110 |
| 2-1/4 | 4 | 0.25000 | 0.1601 | 2.2500 | 2.0899 | 1.9298 | 2.9250 |
| 2-1/2 | 4 | 0.25000 | 0.1601 | 2.5000 | 2.3399 | 2.1798 | 3.7320 |
| 2-3/4 | 3.5 | 0.28571 | 0.1830 | 2.7500 | 2.5670 | 2.3840 | 4.4640 |
| 3 | 3.5 | 0.28571 | 0.1830 | 3.0000 | 2.8170 | 2.6340 | 5.4490 |
| 3-1/4 | 3.25 | 0.30769 | 0.1970 | 3.2500 | 3.0530 | 2.8560 | 6.4060 |
| 3-1/2 | 3.25 | 0.30769 | 0.1970 | 3.5000 | 3.3030 | 3.1060 | 7.5770 |
| 3-3/4 | 3 | 0.33333 | 0.2134 | 3.7500 | 3.5366 | 3.3232 | 8.6740 |
| 4 | 3 | 0.33333 | 0.2134 | 4.0000 | 3.7866 | 3.5732 | 10.0300 |
| 4-1/2 | 2.875 | 0.34783 | 0.2227 | 4.5000 | 4.2773 | 4.0546 | 12.9100 |
| 5 | 2.75 | 0.36364 | 0.2328 | 5.0000 | 4.7672 | 4.5344 | 16.1500 |
| 5-1/2 | 2.625 | 0.38095 | 0.2439 | 5.5000 | 5.2561 | 5.0122 | 19.7300 |
| 6 | 2.5 | 0.40000 | 0.2561 | 6.0000 | 5.7439 | 5.4878 | 23.6500 |
Different between Metric and inch Thread
