British standard pipe BS 1387 : 1967 heavy

Nominal bore		Outside diameter				Thickness		Calculated weight of black tube
		max.	min	max.	min.			Plain End		Screwed and socketed
in	mm	in	in	mm	mm	in	mm	lb/ft	kg/m	lb/ft	kg/m
1/2	15	0.856	0.813	21.7	21.1	0.128	3.25	0.977	1.45	0.983	1.46
3/4	20	1.072	1.047	27.2	26.6	0.128	3.25	1.27	1.9	1.28	1.91
1	25	1.346	1.316	34.2	33.4	0.16	4.05	2	2.97	2.01	2.99
1 1/4	32	1.687	1.657	42.9	42.1	0.16	4.05	2.58	3.84	2.6	3.87
1 1/2	40	1.919	1.889	48.8	48	0.16	4.05	2.98	4.43	3.01	4.47
2	50	2.394	2.354	60.8	59.8	0.176	4.5	4.14	6.17	4.19	6.24
2 1/2	65	3.014	2.969	76.6	75.4	0.176	4.5	5.31	7.9	5.39	8.02
3	80	3.524	3.469	89.5	88.6	0.192	4.85	6.76	10.1	6.87	10.3
3 1/2	90	4.019	3.959	102.1	100.6	0.192	4.85	7.76	11.548	7.88	11.727
4	100	4,524	4.459	114.9	113.3	0.212	5.4	9.71	14.4	9.91	14.7
5	125	5.534	5.459	140.6	138.7	0.212	5.4	12	17.8	12.3	18.3
6	150	6.539	6.459	166.1	164.1	0.212	5.4	14.3	21.2	14.7	21.8