ANSI / ASME B16.5 Class 150 Lap Joint Flange Dimensions

Nominal Pipe Size	Outside Diameter (O)	Thickness (T)	Length Thru Hub (Y)	Hub Diameter (X)	Radius (B)	Bore (B)	Approximate Weight (lbs)	Bolt Circle (C)	Number of Holes	Diameter of Holes
1/2	3.50	0.44	0.63	1.19	0.13	0.90	1	2.38	4	0.63
3/4	3.88	0.50	0.63	1.50	0.13	1.11	2	2.75	4	0.63
1	4.25	0.56	0.69	1.94	0.13	1.38	2	3.13	4	0.63
1 1/4	4.63	0.63	0.81	2.31	0.19	1.72	3	3.50	4	0.63
1 1/2	5.00	0.69	0.88	2.56	0.25	1.97	3	3.88	4	0.63
2	6.00	0.75	1.00	3.06	0.31	2.46	5	4.75	4	0.75
2 1/2	7.00	0.88	1.13	3.56	0.31	2.97	7	5.50	4	0.75
3	7.50	0.94	1.19	4.25	0.38	3.60	8	6.00	4	0.75
3 1/2	8.50	0.94	1.25	4.81	0.38	4.10	11	7.00	8	0.75
4	9.00	0.94	1.31	5.31	0.44	4.60	13	7.50	8	0.75
5	10.00	0.94	1.44	6.44	0.44	5.69	15	8.50	8	0.88
6	11.00	1.00	1.56	7.56	0.50	6.75	19	9.50	8	0.88
8	13.50	1.13	1.75	9.69	0.50	8.75	30	11.75	8	0.88
10	16.00	1.19	1.94	12.00	0.50	10.92	43	14.25	12	1.00
12	19.00	1.25	2.19	14.38	0.50	12.92	64	17.00	12	1.00
14	21.00	1.38	3.13	15.75	0.50	14.18	105	18.75	12	1.13
16	23.50	1.44	3.44	18.00	0.50	16.19	140	21.25	16	1.13
18	25.00	1.56	2.88	19.88	0.50	18.2	160	22.75	16	1.25
20	27.50	1.69	4.06	22.00	0.50	20.25	195	25.00	20	1.25
22	29.50	1.81	4.25	24.25	0.50	22.25	245	27.25	20	1.38
24	32.00	1.88	4.38	26.13	0.50	24.25	275	29.50	20	1.38

*Use 25.4 as a factor to convert into mm.