ANSI / ASME B16.5 Class 150 Blind Flange Dimensions

Nominal Pipe Size	Outside Diameter (O)	Thickness (T)	Raised Face Diameter (R)	Approximate Weight (lbs)	Bolt Circle (C)	Number of Holes	Diameter of Holes
1/2	3.50	0.44	1.38	1	2.38	4	0.63
3/4	3.88	0.50	1.69	2	2.75	4	0.63
1	4.25	0.56	2.00	2	3.13	4	0.63
1 1/4	4.63	0.63	2.50	3	3.50	4	0.63
1 1/2	5.00	0.69	2.88	4	3.88	4	0.63
2	6.00	0.75	3.63	5	4.75	4	0.75
2 1/2	7.00	0.88	4.13	7	5.50	4	0.75
3	7.50	0.94	5.00	9	6.00	4	0.75
3 1/2	8.50	0.94	5.50	13	7.00	8	0.75
4	9.00	0.94	6.19	17	7.50	8	0.75
5	10.00	0.94	7.31	20	8.50	8	0.88
6	11.00	1.00	8.50	26	9.50	8	0.88
8	13.50	1.13	10.63	45	11.75	8	0.88
10	16.00	1.19	12.75	70	14.25	12	1.00
12	19.00	1.25	15.00	110	17.00	12	1.00
14	21.00	1.38	16.25	140	18.75	12	1.13
16	23.50	1.44	18.50	180	21.25	16	1.13
18	25.00	1.56	21.00	220	22.75	16	1.25
20	27.50	1.69	23.00	285	25.00	20	1.25
22	29.50	1.81	25.25	355	27.25	20	1.38
24	32.00	1.88	27.25	430	29.50	20	1.38

Note: All dimensions are in inches, use 25.4 as a factor to convert into mm.