Class 400 Flange Dimensions

Nominal Size	Outside Diameter (OD)	Min. Thickness (T)	RF Dia. (R)	No. of Bolt Holes	Diameter of Holes	Bolt Circle (BC)	SO Bore ID (SB)	Dia. Hub Base (HB)	Dia. Hub Top (HT)	SO LTH (SL)	WN LTH (WL)	* WN Bore ID (WB)
ASME B16 5 Class 400 Flange Dimensions
1⁄2	3.75	0.56	1.38	4	0.63	2.62	0.88	1.5	0.84	0.88	2.06	*
3⁄4	4.62	0.62	1.69	4	0.75	3.25	1.09	1.88	1.05	1.00	2.25	*
1	4.88	0.69	2.00	4	0.75	3.50	1.36	2.12	1.32	1.06	2.44	*
11⁄4	5.25	0.81	2.50	4	0.75	3.88	1.70	2.50	1.66	1.12	2.62	*
11⁄2	6.12	0.88	2.88	4	0.88	4.50	1.95	2.75	1.90	1.25	2.75	*
2	6.50	1.00	3.62	8	0.75	5.00	2.44	3.31	2.38	1.44	2.88	*
21⁄2	7.50	1.12	4.12	8	0.88	5.88	2.94	3.94	2.88	1.62	3.12	*
3	8.25	1.25	5.00	8	0.88	6.62	3.57	4.62	3.50	1.81	3.25	*
31⁄2	9.00	1.38	5.50	8	1.00	7.25	4.07	5.25	4.00	1.94	3.38	*
4	10.00	1.38	6.19	8	1.00	7.88	4.57	5.75	4.50	2.00	3.50	*
5	11.00	1.50	7.31	8	1.00	9.25	5.66	7.00	5.56	2.12	4.00	*
6	12.50	1.62	8.50	12	1.00	10.62	6.72	8.12	6.63	2.25	4.06	*
8	15.00	1.88	10.62	12	1.12	13.00	8.72	10.25	8.63	2.69	4.62	*
10	17.50	2.12	12.75	16	1.25	15.25	10.88	12.62	10.75	2.88	4.88	*
12	20.50	2.25	15.00	16	1.38	17.75	12.88	14.75	12.75	3.12	5.38	*
14	23.00	2.38	16.25	20	1.38	20.25	14.14	16.75	14.00	3.31	5.88	*
16	25.50	2.50	18.50	20	1.50	22.50	16.16	19.00	16.00	3.69	6.00	*
18	28.00	2.62	21.00	24	1.50	24.75	18.18	21.00	18.00	3.88	6.50	*
20	30.50	2.75	23.12	24	1.62	27.00	20.20	23.12	20.00	4.00	6.62	*
22	33.00	2.88	25.25	24	1.75	29.25	22.22	25.25	22.00	4.25	6.75	*
24	36.00	3.00	27.25	24	1.88	32.00	24.25	27.62	24.00	4.50	6.88	*