British Standard Pipe Threads

Nom Bore of Pipe	Dia at Top of Thread	Dia. at Bottom of Thread	No. of Threads per inch
	0.3830	0.3370	28
	0.5180	0.4510	19
	0.6560	0.5890	19
	0.8250	0.7340	14
	0.9020	0.8110	14
	1.041	0.9500	14
	1.189	1.0980	14
1	1.309	1.1930	11
	1.650	1.5340	11
	1.8820	1.7660	11
	2.116	2.0000	11
2	2.347	2.2310	11
	2.5670	2.4710	11
	2.9600	2.8440	11
	3.210	3.0940	11
3	3.460	3.3440	11
	3.7000	3.5840	11
	3.950	3.8340	11
	4.2000	4.0840	11
4	4.450	4.3340	11
	4.950	4.834	11
5	5.450	5.334	11
	5.950	5.834	11
6	6.450	6.334	11
7	7.450	7.322	10
8	8.450	8.322	10
9	9.450	9.322	10
10	10.450	10.322	10
11	11.450	11.290	8
12	12.450	12.290	8
13	13.680	13.520	8
14	14.680	14.520	8
15	15.680	15.520	8
16	16.680	16.520	8
17	17.680	17.520	8
18	18.680	18.520	8

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