ASME B16.5 - Flange Size Chart

Common Dimensions (All Flange Types) - Class 150-2500

Column Legend

NPS = Nominal Pipe Size (inch) DN = Diameter Nominal (mm) OD = Flange Outside Diameter BC = Bolt Circle Diameter RF = Raised Face Diameter n = Number of Bolts d = Bolt Hole Diameter

These dimensions apply to ALL flange types: Welding Neck (WN), Slip-On (SO), Blind (BL), Socket Weld (SW), Lap Joint (LJ), Threaded (TH)

Class 150

NPS	DN	OD	BC	RF	n	d
1/2	15	89	60.3	34.9	4	15.9
3/4	20	98	69.9	42.9	4	15.9
1	25	108	79.4	50.8	4	15.9
1-1/4	32	117	88.9	63.5	4	15.9
1-1/2	40	127	98.4	73	4	15.9
2	50	152	120.7	92.1	4	19.1
2-1/2	65	178	139.7	104.8	4	19.1
3	80	190	152.4	127	4	19.1
3-1/2	90	216	177.8	139.7	8	19.1
4	100	229	190.5	157.2	8	19.1
5	125	254	215.9	185.7	8	22.4
6	150	279	241.3	215.9	8	22.4
8	200	343	298.5	269.9	8	22.4
10	250	406	362	323.9	12	25.4
12	300	483	431.8	381	12	25.4
14	350	533	476.3	412.8	12	28.4
16	400	597	539.8	469.9	16	28.4
18	450	635	577.9	533.4	16	31.8
20	500	698	635	584.2	20	31.8
24	600	813	749.3	692.2	20	35.1

Class 300

NPS	DN	OD	BC	RF	n	d
1/2	15	95	66.7	34.9	4	15.9
3/4	20	117	82.6	42.9	4	19.1
1	25	124	88.9	50.8	4	19.1
1-1/4	32	133	98.4	63.5	4	19.1
1-1/2	40	156	114.3	73	4	22.4
2	50	165	127	92.1	8	19.1
2-1/2	65	190	149.2	104.8	8	22.4
3	80	210	168.3	127	8	22.4
4	100	254	200	157.2	8	22.4
5	125	279	235	185.7	8	22.4
6	150	318	269.9	215.9	12	22.4
8	200	381	330.2	269.9	12	25.4
10	250	444	387.4	323.9	16	28.4
12	300	521	450.9	381	16	31.8
14	350	584	514.4	412.8	20	31.8
16	400	648	571.5	469.9	20	35.1
18	450	711	628.6	533.4	24	35.1
20	500	775	685.8	584.2	24	35.1
24	600	914	812.8	692.2	24	41.1

Class 600

NPS	DN	OD	BC	RF	n	d
1/2	15	95	66.7	34.9	4	15.9
3/4	20	117	82.6	42.9	4	19.1
1	25	124	88.9	50.8	4	19.1
1-1/4	32	133	98.4	63.5	4	19.1
1-1/2	40	156	114.3	73	4	22.4
2	50	165	127	92.1	8	19.1
2-1/2	65	190	149.2	104.8	8	22.4
3	80	210	168.3	127	8	22.4
4	100	273	215.9	157.2	8	25.4
5	125	330	266.7	185.7	8	28.4
6	150	356	292.1	215.9	12	28.4
8	200	419	349.3	269.9	12	31.8
10	250	508	431.8	323.9	16	35.1
12	300	559	489	381	20	35.1
14	350	603	527.1	412.8	20	38.1
16	400	686	603.3	469.9	20	41.1
18	450	743	654.1	533.4	20	44.5
20	500	813	723.9	584.2	24	44.5
24	600	940	838.2	692.2	24	50.8