Machine Specialty & Manufacturing - API Flange Information

2,000 PSI – Type 6B API 6A – Table E.1

Nominal size of Flange	Maximum Bore	Outside Diameter of Flange	Max. Chamfer	Diameter of Raised Face	Total Thickness of Flange	Basic Thickness of Flange	Diameter of Hub	Counter bore Depth
	B	OD	C	K	T	Q	X	E
2 1/16	2.09	6.5	0.12	4.25	1.31	1	3.31	0.31
2 9/16	2.59	7.5	0.12	5	1.44	1.12	3.94	0.31
3 1/8	3.22	8.25	0.12	5.75	1.56	1.25	4.62	0.31
4 1/16	4.28	10.75	0.12	6.88	1.81	1.5	6	0.31
5 1/8	5.16	13	0.12	8.25	2.06	1.75	7.44	0.31
7 1/16	7.16	14	0.25	9.5	2.19	1.88	8.75	0.31
9	9.03	16.5	0.25	11.88	2.5	2.19	10.75	0.31
11	11.03	20	0.25	14	2.81	2.5	13.5	0.31
13 5/8	13.66	22	0.25	16.25	2.94	2.62	15.75	0.31
16 3/4	16.78	27	0.25	20	3.31	3	19.5	0.31
21 1/4	21.28	32	0.25	25	3.88	3.5	24	0.38

3,000 PSI – Type 6B API 6A – Table E.2

Nominal size of Flange	Maximum Bore	Outside Diameter of Flange	Max. Chamfer	Diameter of Raised Face	Total Thickness of Flange	Basic Thickness of Flange	Diameter of Hub	Counter bore Depth
	B	OD	C	K	T	Q	X	E
2 1/16	2.09	8.5	0.12	4.88	1.81	1.5	4.12	0.31
2 9/16	2.59	9.62	0.12	5.38	1.94	1.62	4.88	0.31
3 1/8	3.22	9.5	0.12	6.12	1.81	1.5	5	0.31
4 1/16	4.28	11.5	0.12	7.12	2.06	1.75	6.25	0.31
5 1/8	5.16	13.75	0.12	8.5	2.31	2	7.5	0.31
7 1/16	7.16	15	0.25	9.5	2.5	2.19	9.25	0.31
9	9.03	18.5	0.25	12.12	2.81	2.5	11.75	0.31
11	11.03	21.5	0.25	14.25	3.06	2.75	14.5	0.31
13 5/8	13.66	24	0.25	16.5	3.44	3.12	16.5	0.31
16 3/4	16.78	27.75	0.25	20.62	3.94	3.5	20	0.44
20 3/4	20.78	33.75	0.25	25.5	4.75	4.25	24.5	0.38

5,000 PSI – Type 6B API 6A – Table E.3

Nominal size of Flange	Maximum Bore	Outside Diameter of Flange	Max. Chamfer	Diameter of Raised Face	Total Thickness of Flange	Basic Thickness of Flange	Diameter of Hub	Counter bore Depth
	B	OD	C	K	T	Q	X	E
2 1/16	2.09	8.5	0.12	4.88	1.81	1.5	4.12	0.31
2 9/16	2.59	9.62	0.12	5.38	1.94	1.62	4.88	0.31
3 1/8	3.22	10.5	0.12	6.62	2.19	1.88	5.25	0.31
4 1/16	4.28	12.5	0.12	7.62	2.44	2.12	6.38	0.31
5 1/8	5.16	14.75	0.12	9	3.19	2.88	7.75	0.31
7 1/16	7.16	15.5	0.25	9.75	3.62	3.25	9	0.38
9	9.03	19	0.25	12.5	4.06	3.62	11.5	0.44
11	11.03	23	0.25	14.63	4.69	4.25	14.5	0.44

10,000 PSI – Type 6BX API 6A – Table E.4

Nominal size of Flange	Maximum Bore	Outside Diameter of Flange	Max. Chamfer	Diameter of Raised Face	Total Thickness of Flange	Basic Thickness of Flange	Diameter of Hub	Counter bore Depth	Hub Height
	B	OD	K	T	C	J₁	J₂	J₃	J₄
1 13/16	1.84	7.38	4.12	1.66	0.12	3.5	2.56	1.91	–
2 1/16	2.09	7.88	4.38	1.73	0.12	3.94	2.94	2.03	–
2 9/16	2.59	9.12	5.19	2.02	0.12	4.75	3.62	2.25	–
3 1/16	3.09	10.62	6	2.3	0.12	5.59	4.34	2.5	–
4 1/16	4.09	12.44	7.28	2.77	0.12	7.19	5.75	2.88	–
5 1/8	5.16	14.06	8.69	3.12	0.12	8.81	7.19	3.19	0.25
7 1/16	7.09	18.8	11.88	4.06	0.25	11.88	10	3.75	0.38
9	9.03	21.75	14.12	4.88	0.25	14.75	12.88	3.69	0.38
11	11.03	21.5	0.25	14.25	3.06	2.75	14.5	0.31	–
13 5/8	13.66	30.25	20.38	6.62	0.25	21.75	19.5	4.5	0.69
16 3/4	16.78	34.31	22.69	6.62	0.25	25.81	23.69	3	1.19
18 3/4	18.78	40.94	27.44	8.78	0.25	29.62	26.56	6.12	1
21 1/4	21.28	45	30.75	9.5	0.25	33.38	30	6.5	1.25

15,000 PSI – Type 6BX API 6A – Table E.5

Nominal size of Flange	Maximum Bore	Outside Diameter of Flange	Diameter of Raised Face	Total Thickness of Flange	Max Chamfer	Large Hub Diameter	Small Hub Diameter	Hub Height	Test Flange C’bore Depth
	B	OD	K	T	C	J₁	J₂	J₃	P_h
1 13/16	1.84	8.19	4.19	1.78	0.12	3.84	2.81	1.88	1.98
2 1/16	2.09	8.75	4.5	2	0.12	4.38	3.25	2.12	2.38
2 9/16	2.59	10	5.25	2.25	0.12	5.06	3.94	2.25	2.65
3 1/16	3.09	11.31	6.06	2.53	0.12	5.05	4.81	2.5	3.06
4 1/16	4.09	14.19	7.62	3.09	0.12	7.69	6.25	2.88	3.77
5 1/8	5.16	16.5	8.88	3.88	0.12	9.62	7.88	3.22	4.65
7 1/16	7.09	19.88	12	4.69	0.25	12.81	10.88	3.62	–
9	9.03	25.5	15	5.75	0.25	17	13.75	4.88	–
11	11.03	32	17.88	7.38	0.25	23	16.81	9.28	–
13 5/8	13.66	34.88	21.31	8.06	0.25	23	16.81	9.28	–
18 3/4	18.78	45.75	28.44	10.06	0.25	32	28.75	6.12	–

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