ASME B16.5 Flange STEP Library

Class 900, NPS 2½″ and smaller: please refer to the Class 1500 models — per ASME B16.5 they have identical dimensions. Distinct Class 900 models are provided for NPS 3″ and larger.

Slip-On Flanges (Raised Face) Class 150 · 300 · 600

Class	NPS	Flange OD	Thick	RF OD	BCD	Bolts	Hole ∅	Stud	Pipe OD	Bore	STEP
150	½″	88.9	11.1	34.9	60.3	4	15.88	1/2"	21.34	22.8	↓ STEP
300	½″	95.6	14.3	34.9	66.7	4	15.88	1/2"	21.34	22.8	↓ STEP
600	½″	95.2	14.3	34.9	66.7	4	15.88	1/2"	21.34	22.8	↓ STEP
150	¾″	98.4	12.7	42.9	69.8	4	15.88	1/2"	26.67	28.2	↓ STEP
300	¾″	117.5	15.9	42.9	82.5	4	19.05	5/8"	26.67	28.2	↓ STEP
600	¾″	117.5	15.9	42.9	82.5	4	19.05	5/8"	26.67	28.2	↓ STEP
150	1″	107.9	14.3	50.8	79.4	4	15.88	1/2"	33.4	34.9	↓ STEP
300	1″	123.8	17.5	50.8	88.9	4	19.05	5/8"	33.4	34.9	↓ STEP
600	1″	123.8	17.5	50.8	88.9	4	19.05	5/8"	33.4	34.9	↓ STEP
150	1¼″	117.5	15.9	63.5	88.9	4	15.88	1/2"	42.16	43.7	↓ STEP
300	1¼″	133.3	19	63.5	98.4	4	19.05	5/8"	42.16	43.7	↓ STEP
600	1¼″	133.3	20.6	63.5	98.4	4	19.05	5/8"	42.16	43.7	↓ STEP
150	1½″	127	17.5	73	98.4	4	15.88	1/2"	48.26	49.8	↓ STEP
300	1½″	155.6	20.6	73	114.3	4	22.22	3/4"	48.26	49.8	↓ STEP
600	1½″	155.6	22.2	73	114.3	4	22.22	3/4"	48.26	49.8	↓ STEP
150	2″	152.4	19	92.1	120.6	4	19.05	5/8"	60.33	61.8	↓ STEP
300	2″	165.1	22.2	92.1	127	8	19.05	5/8"	60.33	61.8	↓ STEP
600	2″	165.1	25.4	92.1	127	8	19.05	5/8"	60.33	61.8	↓ STEP
150	2½″	177.8	22.2	104.8	139.7	4	19.05	5/8"	73.03	74.5	↓ STEP
300	2½″	190.5	25.4	104.8	149.2	8	22.22	3/4"	73.03	74.5	↓ STEP
600	2½″	190.5	28.6	104.8	149.2	8	22.22	3/4"	73.03	74.5	↓ STEP
150	3″	190.5	23.8	127	152.4	4	19.05	5/8"	88.9	90.4	↓ STEP
300	3″	209.5	28.6	127	168.3	8	22.22	3/4"	88.9	90.4	↓ STEP
600	3″	209.5	31.7	127	168.3	8	22.22	3/4"	88.9	90.4	↓ STEP
150	4″	228.6	23.8	157.2	190.5	8	19.05	5/8"	114.3	115.8	↓ STEP
300	4″	254	31.7	157.2	200	8	22.22	3/4"	114.3	115.8	↓ STEP
600	4″	273	38.1	157.2	215.9	8	25.4	7/8"	114.3	115.8	↓ STEP
150	6″	279.4	25.4	215.9	241.3	8	22.22	3/4"	168.28	169.8	↓ STEP
300	6″	317.5	36.5	215.9	269.9	12	22.22	3/4"	168.28	169.8	↓ STEP
600	6″	355.6	47.6	215.9	292.1	12	28.57	1"	168.28	169.8	↓ STEP
150	8″	342.9	28.6	269.9	298.4	8	22.22	3/4"	219.08	220.6	↓ STEP
300	8″	381	41.3	269.9	330.2	12	25.4	7/8"	219.08	220.6	↓ STEP
600	8″	419.1	55.6	269.9	349.2	12	31.75	1-1/8"	219.08	220.6	↓ STEP
150	10″	406.4	30.2	323.8	361.9	12	25.4	7/8"	273.05	274.6	↓ STEP
300	10″	444.5	47.6	323.8	387.3	16	28.57	1"	273.05	274.6	↓ STEP
600	10″	508	63.5	323.8	431.8	16	34.92	1-1/4"	273.05	274.6	↓ STEP
150	12″	482.6	31.7	381	431.8	12	25.4	7/8"	323.85	325.4	↓ STEP
300	12″	520.7	50.8	381	450.8	16	31.75	1-1/8"	323.85	325.4	↓ STEP
600	12″	558.8	66.7	381	488.9	20	34.92	1-1/4"	323.85	325.4	↓ STEP
150	14″	533.4	34.9	412.7	476.2	12	28.57	1"	355.6	357.1	↓ STEP
300	14″	584.2	54	412.7	514.3	20	31.75	1-1/8"	355.6	357.1	↓ STEP
600	14″	603.2	69.8	412.7	527	20	38.1	1-3/8"	355.6	357.1	↓ STEP
150	16″	596.9	36.5	469.9	539.7	16	28.57	1"	406.4	407.9	↓ STEP
300	16″	647.7	57.1	469.9	571.5	20	34.92	1-1/4"	406.4	407.9	↓ STEP
600	16″	685.8	76.2	469.9	603.2	20	41.27	1-1/2"	406.4	407.9	↓ STEP

Weld Neck Flanges — Raised Face Class 150 · 300 · 600 · 900 · 1500

Three bore options per size: SCH40, SCH80, or Solid (no bore — machine to any schedule in your CAD tool).

Class	NPS	OD	Thick	Hub	Hub OD	Pipe OD	RF OD	BCD	Bolts	Hole ∅	Stud	SCH40	SCH80	Solid
150	1″	108	14.2	41.4	49.3	33.5	50.8	79.4	4	15.88	1/2"	↓	↓	↓
300	1″	124	17.5	44.5	53.8	33.5	50.8	88.9	4	19.05	5/8"	↓	↓	↓
600	1″	124	17.5	44.5	53.8	33.5	50.8	88.9	4	19.05	5/8"	↓	↓	↓
1500	1″	149.4	28.7	44.5	52.3	33.5	50.8	101.6	4	25.4	7/8"	↓	↓	↓
150	1¼″	117	15.7	41.5	58.7	42.2	63.5	88.9	4	15.88	1/2"	↓	↓	↓
300	1¼″	133	19.1	45.9	63.5	42.2	63.5	98.4	4	19.05	5/8"	↓	↓	↓
600	1¼″	133	20.6	45.9	63.5	42.2	63.5	98.4	4	19.05	5/8"	↓	↓	↓
1500	1¼″	158.8	28.7	44.5	63.5	42.2	63.5	111.1	4	25.4	7/8"	↓	↓	↓
150	1½″	127	17.5	44.5	65	48.3	73.2	98.4	4	15.88	1/2"	↓	↓	↓
300	1½″	155	20.6	47.7	69.9	48.3	73.2	114.3	4	22.22	3/4"	↓	↓	↓
600	1½″	155	22.4	47.5	69.9	48.3	73.2	114.3	4	22.22	3/4"	↓	↓	↓
1500	1½″	177.8	31.8	50.8	69.9	48.3	73.2	123.8	4	28.6	1"	↓	↓	↓
150	2″	152	19.1	44.4	77.7	60.5	91.9	120.6	4	19.05	5/8"	↓	↓	↓
300	2″	165	22.1	47.8	84.1	60.5	91.9	127	8	19.05	5/8"	↓	↓	↓
600	2″	165	25.4	47.8	84.1	60.5	91.9	127	8	19.05	5/8"	↓	↓	↓
1500	2″	215.9	38.1	63.5	104.9	60.5	92.2	165.1	8	25.4	7/8"	↓	↓	↓
150	2½″	178	22.4	47.5	90.4	73.2	104.6	139.7	4	19.05	5/8"	↓	↓	↓
300	2½″	191	25.4	50.8	100.1	73.2	104.6	149.2	8	22.22	3/4"	↓	↓	↓
600	2½″	191	28.4	50.8	100.1	73.2	104.6	149.2	8	22.22	3/4"	↓	↓	↓
1500	2½″	244.5	41.4	61.7	123.8	73.2	104.9	190.5	8	28.6	1"	↓	↓	↓
150	3″	191	23.9	46	108	88.9	127	152.4	4	19.05	5/8"	↓	↓	↓
300	3″	210	28.4	50.8	117.3	88.9	127	168.3	8	22.22	3/4"	↓	↓	↓
600	3″	210	31.8	50.8	117.3	88.9	127	168.3	8	22.22	3/4"	↓	↓	↓
900	3″	241.3	38.1	63.5	127	88.9	127	190.5	8	25.4	7/8"	↓	↓	↓
1500	3″	266.7	47.8	69.7	133.4	88.9	127	203.2	8	31.8	1-1/8"	↓	↓	↓
150	4″	229	23.9	52.3	134.9	114.3	157.2	190.5	8	19.05	5/8"	↓	↓	↓
300	4″	254	31.8	54.1	146.1	114.3	157.2	200	8	22.22	3/4"	↓	↓	↓
600	4″	273	38.1	63.5	152.4	114.3	157.2	215.9	8	25.4	7/8"	↓	↓	↓
900	4″	292.1	44.5	69.8	158.8	114.3	157.2	235	8	31.8	1-1/8"	↓	↓	↓
1500	4″	311.2	54.1	69.9	162.1	114.3	157.2	241.3	8	35	1-1/4"	↓	↓	↓
150	6″	279	25.4	63.5	192	168.4	215.9	241.3	8	22.22	3/4"	↓	↓	↓
300	6″	318	36.6	62	206.2	168.4	215.9	269.9	12	22.22	3/4"	↓	↓	↓
600	6″	356	47.8	69.5	222.3	168.4	215.9	292.1	12	28.57	1"	↓	↓	↓
900	6″	381	55.6	84.1	235	168.4	215.9	317.5	12	31.8	1-1/8"	↓	↓	↓
1500	6″	393.7	82.6	88.9	228.6	168.3	215.9	317.5	12	38.1	1-3/8"	↓	↓	↓
150	8″	343	28.4	73.2	246.1	219.2	269.7	298.4	8	22.22	3/4"	↓	↓	↓
300	8″	381	41.1	70.2	260.4	219.2	269.7	330.2	12	25.4	7/8"	↓	↓	↓
600	8″	419	55.6	77.8	273.1	219.2	269.7	349.2	12	31.75	1-1/8"	↓	↓	↓
900	8″	469.9	63.5	98.6	298.5	219.2	270	393.7	12	38.1	1-3/8"	↓	↓	↓
1500	8″	482.6	92.2	120.7	292.1	219.1	270	393.7	12	44.5	1-5/8"	↓	↓	↓
150	10″	406	30.2	71.4	304.8	273.1	323.9	361.9	12	25.4	7/8"	↓	↓	↓
300	10″	445	47.8	69.5	320.5	273.1	323.9	387.3	16	28.57	1"	↓	↓	↓
600	10″	508	63.5	88.9	342.9	273.1	323.9	431.8	16	34.92	1-1/4"	↓	↓	↓
900	10″	546.1	69.9	114.3	368.3	273.1	323.9	469.9	16	38.1	1-3/8"	↓	↓	↓
1500	10″	584.2	108	146	368.3	273.1	323.9	482.6	12	50.8	1-7/8"	↓	↓	↓
150	12″	483	31.8	82.5	365.3	323.9	381	431.8	12	25.4	7/8"	↓	↓	↓
300	12″	521	50.8	79.2	374.7	323.9	381	450.8	16	31.75	1-1/8"	↓	↓	↓
600	12″	559	66.5	88.9	400.1	323.9	381	488.9	20	34.92	1-1/4"	↓	↓	↓
900	12″	609.6	79.5	120.7	419.1	323.9	381	533.4	20	38.1	1-3/8"	↓	↓	↓
1500	12″	673.1	124	158.7	450.9	323.9	381	571.5	16	54.1	2"	↓	↓	↓
150	14″	533	35.1	91.9	400.1	355.6	412.8	476.2	12	28.57	1"	↓	↓	↓
300	14″	584	53.8	88.9	425.5	355.6	412.8	514.3	20	31.75	1-1/8"	↓	↓	↓
600	14″	603	69.9	95.2	431.8	355.6	412.8	527	20	38.1	1-3/8"	↓	↓	↓
900	14″	641.4	85.9	127	450.9	355.6	412.8	558.8	20	44.6	1-5/8"	↓	↓	↓
1500	14″	749.3	133.4	165.1	495.3	355.6	412.8	635	16	60.3	2-1/4"	↓	↓	↓
150	16″	597	36.6	90.4	457.2	406.4	469.9	539.7	16	28.57	1"	↓	↓	↓
300	16″	648	57.2	88.9	482.6	406.4	469.9	571.5	20	34.92	1-1/4"	↓	↓	↓
600	16″	686	76.2	101.6	495.3	406.4	469.9	603.2	20	41.27	1-1/2"	↓	↓	↓
900	16″	704.9	88.9	127	508	406.4	469.9	615.9	20	47.7	1-3/4"	↓	↓	↓
1500	16″	825.5	146.1	165.1	552.5	406.4	469.9	704.9	16	66.8	2-1/2"	↓	↓	↓

Weld Neck Flanges — Ring Type Joint Class 150 · 300 · 600 · 900 · 1500

RTJ groove per ASME B16.5 Fig. 2 (23° wall angle). Ring number shown for groove/gasket selection. Download matching ring gasket models from the RTJ Ring Gasket Library.

Class	NPS	OD	Thick	Hub	Hub OD	Pipe OD	RF OD	BCD	Bolts	Hole ∅	Stud	Ring	SCH40	SCH80	Solid
150	1″	108	14.2	41.4	49.3	33.5	50.8	79.4	4	15.88	1/2"	R15	↓	↓	↓
300	1″	124	17.5	44.5	53.8	33.5	50.8	88.9	4	19.05	5/8"	R16	↓	↓	↓
600	1″	124	17.5	44.5	53.8	33.5	50.8	88.9	4	19.05	5/8"	R16	↓	↓	↓
1500	1″	149.4	28.7	44.5	52.3	33.5	50.8	101.6	4	25.4	7/8"	R16	↓	↓	↓
150	1¼″	117	15.7	41.5	58.7	42.2	63.5	88.9	4	15.88	1/2"	R17	↓	↓	↓
300	1¼″	133	19.1	45.9	63.5	42.2	63.5	98.4	4	19.05	5/8"	R18	↓	↓	↓
600	1¼″	133	20.6	45.9	63.5	42.2	63.5	98.4	4	19.05	5/8"	R18	↓	↓	↓
1500	1¼″	158.8	28.7	44.5	63.5	42.2	63.5	111.1	4	25.4	7/8"	R18	↓	↓	↓
150	1½″	127	17.5	44.5	65	48.3	73.2	98.4	4	15.88	1/2"	R19	↓	↓	↓
300	1½″	155	20.6	47.7	69.9	48.3	73.2	114.3	4	22.22	3/4"	R20	↓	↓	↓
600	1½″	155	22.4	47.5	69.9	48.3	73.2	114.3	4	22.22	3/4"	R20	↓	↓	↓
1500	1½″	177.8	31.8	50.8	69.9	48.3	73.2	123.8	4	28.6	1"	R20	↓	↓	↓
150	2″	152	19.1	44.4	77.7	60.5	91.9	120.6	4	19.05	5/8"	R22	↓	↓	↓
300	2″	165	22.1	47.8	84.1	60.5	91.9	127	8	19.05	5/8"	R23	↓	↓	↓
600	2″	165	25.4	47.8	84.1	60.5	91.9	127	8	19.05	5/8"	R23	↓	↓	↓
1500	2″	215.9	38.1	63.5	104.9	60.5	92.2	165.1	8	25.4	7/8"	R24	↓	↓	↓
150	2½″	178	22.4	47.5	90.4	73.2	104.6	139.7	4	19.05	5/8"	R25	↓	↓	↓
300	2½″	191	25.4	50.8	100.1	73.2	104.6	149.2	8	22.22	3/4"	R26	↓	↓	↓
600	2½″	191	28.4	50.8	100.1	73.2	104.6	149.2	8	22.22	3/4"	R26	↓	↓	↓
1500	2½″	244.5	41.4	61.7	123.8	73.2	104.9	190.5	8	28.6	1"	R27	↓	↓	↓
150	3″	191	23.9	46	108	88.9	127	152.4	4	19.05	5/8"	R29	↓	↓	↓
300	3″	210	28.4	50.8	117.3	88.9	127	168.3	8	22.22	3/4"	R31	↓	↓	↓
600	3″	210	31.8	50.8	117.3	88.9	127	168.3	8	22.22	3/4"	R31	↓	↓	↓
900	3″	241.3	38.1	63.5	127	88.9	127	190.5	8	25.4	7/8"	R31	↓	↓	↓
1500	3″	266.7	47.8	69.7	133.4	88.9	127	203.2	8	31.8	1-1/8"	R35	↓	↓	↓
150	4″	229	23.9	52.3	134.9	114.3	157.2	190.5	8	19.05	5/8"	R36	↓	↓	↓
300	4″	254	31.8	54.1	146.1	114.3	157.2	200	8	22.22	3/4"	R37	↓	↓	↓
600	4″	273	38.1	63.5	152.4	114.3	157.2	215.9	8	25.4	7/8"	R37	↓	↓	↓
900	4″	292.1	44.5	69.8	158.8	114.3	157.2	235	8	31.8	1-1/8"	R37	↓	↓	↓
1500	4″	311.2	54.1	69.9	162.1	114.3	157.2	241.3	8	35	1-1/4"	R39	↓	↓	↓
150	6″	279	25.4	63.5	192	168.4	215.9	241.3	8	22.22	3/4"	R43	↓	↓	↓
300	6″	318	36.6	62	206.2	168.4	215.9	269.9	12	22.22	3/4"	R45	↓	↓	↓
600	6″	356	47.8	69.5	222.3	168.4	215.9	292.1	12	28.57	1"	R45	↓	↓	↓
900	6″	381	55.6	84.1	235	168.4	215.9	317.5	12	31.8	1-1/8"	R45	↓	↓	↓
1500	6″	393.7	82.6	88.9	228.6	168.3	215.9	317.5	12	38.1	1-3/8"	R46	↓	↓	↓
150	8″	343	28.4	73.2	246.1	219.2	269.7	298.4	8	22.22	3/4"	R48	↓	↓	↓
300	8″	381	41.1	70.2	260.4	219.2	269.7	330.2	12	25.4	7/8"	R49	↓	↓	↓
600	8″	419	55.6	77.8	273.1	219.2	269.7	349.2	12	31.75	1-1/8"	R49	↓	↓	↓
900	8″	469.9	63.5	98.6	298.5	219.2	270	393.7	12	38.1	1-3/8"	R49	↓	↓	↓
1500	8″	482.6	92.2	120.7	292.1	219.1	270	393.7	12	44.5	1-5/8"	R50	↓	↓	↓
150	10″	406	30.2	71.4	304.8	273.1	323.9	361.9	12	25.4	7/8"	R52	↓	↓	↓
300	10″	445	47.8	69.5	320.5	273.1	323.9	387.3	16	28.57	1"	R53	↓	↓	↓
600	10″	508	63.5	88.9	342.9	273.1	323.9	431.8	16	34.92	1-1/4"	R53	↓	↓	↓
900	10″	546.1	69.9	114.3	368.3	273.1	323.9	469.9	16	38.1	1-3/8"	R53	↓	↓	↓
1500	10″	584.2	108	146	368.3	273.1	323.9	482.6	12	50.8	1-7/8"	R54	↓	↓	↓
150	12″	483	31.8	82.5	365.3	323.9	381	431.8	12	25.4	7/8"	R56	↓	↓	↓
300	12″	521	50.8	79.2	374.7	323.9	381	450.8	16	31.75	1-1/8"	R57	↓	↓	↓
600	12″	559	66.5	88.9	400.1	323.9	381	488.9	20	34.92	1-1/4"	R57	↓	↓	↓
900	12″	609.6	79.5	120.7	419.1	323.9	381	533.4	20	38.1	1-3/8"	R57	↓	↓	↓
1500	12″	673.1	124	158.7	450.9	323.9	381	571.5	16	54.1	2"	R58	↓	↓	↓
150	14″	533	35.1	91.9	400.1	355.6	412.8	476.2	12	28.57	1"	R59	↓	↓	↓
300	14″	584	53.8	88.9	425.5	355.6	412.8	514.3	20	31.75	1-1/8"	R61	↓	↓	↓
600	14″	603	69.9	95.2	431.8	355.6	412.8	527	20	38.1	1-3/8"	R61	↓	↓	↓
900	14″	641.4	85.9	127	450.9	355.6	412.8	558.8	20	44.6	1-5/8"	R62	↓	↓	↓
1500	14″	749.3	133.4	165.1	495.3	355.6	412.8	635	16	60.3	2-1/4"	R63	↓	↓	↓
150	16″	597	36.6	90.4	457.2	406.4	469.9	539.7	16	28.57	1"	R64	↓	↓	↓
300	16″	648	57.2	88.9	482.6	406.4	469.9	571.5	20	34.92	1-1/4"	R65	↓	↓	↓
600	16″	686	76.2	101.6	495.3	406.4	469.9	603.2	20	41.27	1-1/2"	R65	↓	↓	↓
900	16″	704.9	88.9	127	508	406.4	469.9	615.9	20	47.7	1-3/4"	R66	↓	↓	↓
1500	16″	825.5	146.1	165.1	552.5	406.4	469.9	704.9	16	66.8	2-1/2"	R67	↓	↓	↓

Notes

All dimensions in millimetres. Data sourced from third-party references; always verify against the official ASME B16.5 current edition.
SO bore = pipe OD + 1.5 mm slip clearance per standard practice.
WN hub tapers from pipe OD at weld end to hub base OD at flange disc.
RF height: 1.6 mm for Class 150–600, 6.35 mm for Class 900.
RTJ groove: 23° wall angle per ASME B16.5 Fig. 2. Ring number shown; groove dimensions from ASME B16.20.
“Solid” = no bore (NOBORE) — hub is solid, allowing the user to machine any schedule bore in their own CAD environment.
Bolt holes straddle principal axes per ASME B16.5 requirement.
Bolt hole diameter = stud diameter + 3.18 mm (&frac18;″) per ASME B16.5.