ANSI / ASME B16.5 Class 300 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	3.75	0.56	1.38	2	2.63	4	0.63
3/4	4.63	0.63	1.69	3	3.25	4	0.75
1	4.88	0.69	2.00	3	3.50	4	0.75
1 1/4	5.25	0.75	2.50	4	3.88	4	0.75
1 1/2	6.13	0.81	2.88	6	4.50	4	0.88
2	6.50	0.88	3.63	8	5.00	8	0.75
2 1/2	7.50	1.00	4.13	12	5.88	8	0.88
3	8.25	1.13	5.00	16	6.63	8	0.88
3 1/2	9.00	1.19	5.50	21	7.25	8	0.88
4	10.00	1.25	6.19	27	7.88	8	0.88
5	11.00	1.38	7.31	35	9.25	8	0.88
6	12.50	1.44	8.50	50	10.63	12	0.88
8	15.00	1.63	10.63	81	13.00	12	1.00
10	17.50	1.88	12.75	124	15.25	16	1.13
12	20.50	2.00	15.00	185	17.75	16	1.25
14	23.00	2.13	16.25	250	20.25	20	1.25
16	25.50	2.25	18.50	295	22.50	20	1.38
18	28.00	2.38	21.00	395	24.75	24	1.38
20	30.50	2.50	23.00	505	27.00	24	1.38
22	33.00	2.63	25.25	640	29.25	24	1.63
24	36.00	2.75	27.25	790	32.00	24	1.63

*Use 25.4 as a factor to convert into mm.