The Mechanical
Engineering Handbook




BSP Thread Sizes and Dimensions

Size Chart



BSP Thread Size Diameter (mm) Diameter (inch) Pitch (TPI)
1/16" 7.7 0.304" 28
1/8" 9.7 0.383" 28
1/4" 13.16 0.518" 19
3/8" 16.66 0.656" 19
1/2" 20.99 0.825" 14
5/8" 22.99 0.902" 14
3/4" 26.44 1.041" 14
7/8" 30.20 1.189" 14
1" 33.25 1.309" 11
1-1/4" 41.91 1.650" 11
1-1/2" 47.80 1.882" 11
2" 59.61 2.347" 11
2-1/4" 65.71 2.587" 11
2-1/2" 75.18 2.96" 11
3" 87.88 3.46" 11
4" 113.03 4.45" 11
5" 138.43 5.45" 11
6" 163.83 6.45" 11

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