Common Flange Specifications by Size
See Common Flange Specs by Type
See legend below for explanations
NW 16 CF/Mini
| Flange I.D. (max) | 0.630 (16) |
| Flange O.D. | 1.33 (34) |
| Bolt Circle | 1.063 (27) |
| Bolt Hole | 0.169 (4.3) |
| # of Bolts | 6 |
| # of Clamps | None Required |
| Bolt Size | 832 x 3/4 (#) |
NW 25 CF/2-1/8"
| Flange I.D. (max) | 0.88 (22.2) |
| Flange O.D. | 2.11 (53.6) |
| Bolt Circle | 1.625 (41.3) |
| Bolt Hole | 0.265 (6.7) |
| # of Bolts | 4 |
| # of Clamps | None Required |
| Bolt Size | 1/4-28 x 1 1/4 (#) |
NW 35 CF/2-3/4″
| Flange I.D. (max) | 1.500 (38.1) |
| Flange O.D. | 2.75 (69.9) |
| Bolt Circle | 2.312 (58.7) |
| Bolt Hole | 0.265 (6.7) |
| # of Bolts | 6 |
| # of Clamps | None Required |
| Bolt Size | 1/4-28 x 1 1/4 (#) |
NW 50 CF/3-3/8″
| Flange I.D. (max) |
1.88 (47.6) |
| Flange O.D. |
3.37 (85.6) |
| Bolt Circle |
2.850 (72.4) |
| Bolt Hole |
0.332 (8.4) |
| # of Bolts | 8 |
| # of Clamps | None Required |
| Bolt Size |
5/16-24 x 2 (#) |
1.5″ ASA
| Flange I.D. (max) | 2.200 (55.9) |
| Flange O.D. | 5.00 (127.0) |
| Bolt Circle | 3.875 (98.4) |
| Bolt Hole | 0.62 (15.9) |
| # of Bolts | 4 |
| # of Clamps | None Required |
| Bolt Size | 1/2-13 x 1 1/2 |
NW 63 ISO-F
| Flange I.D. (max) | 2.37 (60.20) |
| Flange O.D. | 3.74 (95.0) |
| Bolt Circle | — |
| Bolt Hole | 0.35 (8.9) (+) |
| # of Bolts | 4 |
| # of Clamps | 4 (++) |
| Bolt Size | M8 x 40 |
NW 63 ISO-Bolt Flange
| Flange I.D. (max) | 2.37 (60.20) |
| Flange O.D. | 5.12 (130) |
| Bolt Circle | 4.331 (110) |
| Bolt Hole | M8 |
| # of Bolts | 4 |
| # of Clamps | 4 |
| Bolt Size | M8 x 40 |
NW 63 CF/4 1/2″
| Flange I.D. (max) | 2.500 (63.5) |
| Flange O.D. | 4.47 (113.5) |
| Bolt Circle | 3.628 (92.2) |
| Bolt Hole | 0.332 (8.4) |
| # of Bolts | 8 |
| # of Clamps | None Required |
| Bolt Size | 5/16-24 x 2 (#) |
NW 80 ISO-F
| Flange I.D. (max) | 2.87 (72.90) |
| Flange O.D. | 4.33 (110) |
| Bolt Circle | — |
| Bolt Hole | 0.35 (8.9) (+) |
| # of Bolts | 4 |
| # of Clamps | 4 (++) |
| Bolt Size | M8 x 40 |
NW 80 ISO-Bolt Flange
| Flange I.D. (max) | 2.87 (72.90) |
| Flange O.D. | 5.71 (145) |
| Bolt Circle | 4.920 (125) |
| Bolt Hole | M8 |
| # of Bolts | 4 |
| # of Clamps | 4 |
| Bolt Size | M8 x 40 |
NW 75 CF/4 5/8″
| Flange I.D. (max) | 2.88 (73) |
| Flange O.D. | 4.62 (117.35) |
| Bolt Circle | 4.030 (102.4) |
| Bolt Hole | 0.332 (8.4) |
| # of Bolts | 10 |
| # of Clamps | None Required |
| Bolt Size | 5/16-24 x 2 (#) |
2″ ASA
| Flange I.D. (max) | 3.00 (76.2) |
| Flange O.D. | 6.00 (152.6) |
| Bolt Circle | 4.750 (120.7) |
| Bolt Hole | 0.75 (19.1) |
| # of Bolts | 4 |
| # of Clamps | None Required |
| Bolt Size | 5/8-11 x 1 3/4 |
NW 100 ISO-F
| Flange I.D. (max) | 3.83 (97.28) |
| Flange O.D. | 5.12 (130) |
| Bolt Circle | — |
| Bolt Hole | 0.35 (8.9) (+) |
| # of Bolts | 4 |
| # of Clamps | 4 (++) |
| Bolt Size | M8 x 40 |
NW 100 ISO-Bolt Flange
| Flange I.D. (max) | 3.83 (97.28) |
| Flange O.D. | 6.496 (165) |
| Bolt Circle | 5.709 (145) |
| Bolt Hole | M8 |
| # of Bolts | 8 |
| # of Clamps | 4 |
| Bolt Size | M8 x 40 |
NW 100 CF/6″
| Flange I.D. (max) | 4.00 (101.6) |
| Flange O.D. | 5.97 (151.6) |
| Bolt Circle | 5.128 (130.3) |
| Bolt Hole | 0.332 (8.4) |
| # of Bolts | 16 |
| # of Clamps | None Required |
| Bolt Size | 5/16-24 x 2 1/4 (#) |
3″ ASA
| Flange I.D. (max) | 4.20 (107) |
| Flange O.D. | 7.50 (190.5) |
| Bolt Circle | 6.00 (152.4) |
| Bolt Hole | 0.75 (19.1) |
| # of Bolts | 8 |
| # of Clamps | None Required |
| Bolt Size | 5/8-11 x 1 3/4 |
NW 130 CF/6 3/4″
| Flange I.D. (max) | 4.87 (123.7) |
| Flange O.D. | 6.75 (171.45) |
| Bolt Circle | 5.969 (151.6) |
| Bolt Hole | 0.332 (8.4) |
| # of Bolts | 18 |
| # of Clamps | None Required |
| Bolt Size | 5/16-24 x 2 1/4 (#) |
4″ ASA
| Flange I.D. (max) | 5.70 (145) |
| Flange O.D. | 9.00 (228.6) |
| Bolt Circle | 7.500 (190.5) |
| Bolt Hole | 0.75 (19.1) |
| # of Bolts | 8 |
| # of Clamps | None Required |
| Bolt Size | 5/8-11 x 1 3/4 |
NW 160 ISO-F
| Flange I.D. (max) | 5.87 (149.10) |
| Flange O.D. | 7.09 (180) |
| Bolt Circle | — |
| Bolt Hole | 0.43 (10.9) (+) |
| # of Bolts | 4 |
| # of Clamps | 4 (++) |
| Bolt Size | M10 x 50 |
NW 160 ISO-Bolt Flange
| Flange I.D. (max) | 5.87 (149.10) |
| Flange O.D. | 8.858 (225) |
| Bolt Circle | 7.874 (200) |
| Bolt Hole | M10 |
| # of Bolts | 8 |
| # of Clamps | 4 |
| Bolt Size | M10 x 50 |
NW 150 CF/8″
| Flange I.D. (max) | 6.00 (152.4) |
| Flange O.D. | 7.97 (202.4) |
| Bolt Circle | 7.128 (181.1) |
| Bolt Hole | 0.332 (8.4) |
| # of Bolts | 20 |
| # of Clamps | None Required |
| Bolt Size | 3/16-24 x 2 1/4 (#) |
6″ ASA
| Flange I.D. (max) | 7.6 (193) |
| Flange O.D. | 11.0 (279.4) |
| Bolt Circle | 9.500 (241.3) |
| Bolt Hole | 0.81 (20.6) |
| # of Bolts | 8 |
| # of Clamps | None Required |
| Bolt Size | 3/4-10 x 2 1/4 |
NW 200 ISO-F
| Flange I.D. (max) | 7.83 (198.90) |
| Flange O.D. | 9.45 (240) |
| Bolt Circle | — |
| Bolt Hole | 0.43 (10.9) (+) |
| # of Bolts | 6 |
| # of Clamps | 6 (++) |
| Bolt Size | M10 x 50 |
NW 200 ISO-Bolt Flange
| Flange I.D. (max) | 7.83 (198.90) |
| Flange O.D. | 11.22 (285) |
| Bolt Circle | 10.236 (260) |
| Bolt Hole | M10 |
| # of Bolts | 12 |
| # of Clamps | 6 |
| Bolt Size | M10 x 50 |
NW 200 CF/10″
| Flange I.D. (max) | 8.00 (203.2) |
| Flange O.D. | 9.97 (253.2) |
| Bolt Circle | 9.128 (231.9) |
| Bolt Hole | 0.332 (8.4) |
| # of Bolts | 24 |
| # of Clamps | None Required |
| Bolt Size | 5/16-24 x 2 1/2 (#) |
NW 250 ISO-F
| Flange I.D. (max) | 12.42 (315.47) |
| Flange O.D. | 14.57 (370) |
| Bolt Circle | — |
| Bolt Hole | 0.43 (10.9) (+) |
| # of Bolts | 6 |
| # of Clamps | 6 (++) |
| Bolt Size | M10 x 50 |
NW 250 ISO-Bolt Flange
| Flange I.D. (max) | 9.75 (247.65) |
| Flange O.D. | 13.189 (335) |
| Bolt Circle | 12.205 (310) |
| Bolt Hole | M10 |
| # of Bolts | 12 |
| # of Clamps | 6 |
| Bolt Size | M10 x 50 |
NW 250 CF/12″
| Flange I.D. (max) | 9.843 (250.0) |
| Flange O.D. | 12.05 (306) |
| Bolt Circle | 11.18 (284) |
| Bolt Hole | 0.332 (8.4) |
| # of Bolts | 32 |
| # of Clamps | None Required |
| Bolt Size | 5/16-24 x 2 1/2 (#) |
8″ ASA
| Flange I.D. (max) | 10.276 (261.0) |
| Flange O.D. | 13.50 (342.9) |
| Bolt Circle | 11.750 (298.5) |
| Bolt Hole | 0.81 (20.6) |
| # of Bolts | 8 |
| # of Clamps | None Required |
| Bolt Size | 3/4-10 x 2 1/4 |
NW 275 CF/13 1/4″
| Flange I.D. (max) | 10.63 (270) |
| Flange O.D. | 13.25 (336.55) |
| Bolt Circle | 12.06 (306.3) |
| Bolt Hole | 0.390 (9.9) |
| # of Bolts | 30 |
| # of Clamps | None Required |
| Bolt Size | 3/8-24 x 2 1/2 (#) |
10″ ASA
| Flange I.D. (max) | 12.00 (304.8) |
| Flange O.D. | 16.00 (406.4) |
| Bolt Circle | 14.250 (362) |
| Bolt Hole | 0.81 (20.6) |
| # of Bolts | 12 |
| # of Clamps | None Required |
| Bolt Size | 3/4-10 x 2 1/4 |
NW 320 ISO-F
| Flange I.D. (max) | 12.42 (315.47) |
| Flange O.D. | 14.57 (370) |
| Bolt Circle | — |
| Bolt Hole | 0.51 (13.0) (+) |
| # of Bolts | 8 |
| # of Clamps | 8 (++) |
| Bolt Size | M12 x 60 |
NW 320 ISO-Bolt Flange
| Flange I.D. (max) | 12.42 (315.47) |
| Flange O.D. | 16.732 (425) |
| Bolt Circle | 15.551 (395) |
| Bolt Hole | M12 |
| # of Bolts | 12 |
| # of Clamps | 8 |
| Bolt Size | M12 x 60 |
NW 400 ISO-F
| Flange I.D. (max) | 15.50 (393.70) |
| Flange O.D. | 17.72 (450) |
| Bolt Circle | — |
| Bolt Hole | 0.51 (13.0) (+) |
| # of Bolts | 8 |
| # of Clamps | 8 (++) |
| Bolt Size | M12 x 60 |
NW 400 ISO-Bolt Flange
| Flange I.D. (max) | 15.50 (393.70) |
| Flange O.D. | 20.08 (510) |
| Bolt Circle | 18.90 (480) |
| Bolt Hole | M12 |
| # of Bolts | 16 |
| # of Clamps | 8 |
| Bolt Size | M12 x 60 |
16″ ASA
| Flange I.D. (max) | 18.00 (457.2) |
| Flange O.D. | 23.50 (596.9) |
| Bolt Circle | 21.25 (539.5) |
| Bolt Hole | 1.12 (28) |
| # of Bolts | 16 |
| # of Clamps | None Required |
| Bolt Size | 7/8-9 x 3 |
NW 500 ISO-F
| Flange I.D. (max) | 19.50 (495.30) |
| Flange O.D. | 21.65 (550) |
| Bolt Circle | — |
| Bolt Hole | 0.51 (13.0) (+) |
| # of Bolts | 12 |
| # of Clamps | 12 (++) |
| Bolt Size | M12 x 60 |
NW 500 ISO-Bolt Flange
| Flange I.D. (max) | 19.50 (495.30) |
| Flange O.D. | 24.02 (610) |
| Bolt Circle | 22.83 (580) |
| Bolt Hole | M12 |
| # of Bolts | 16 |
| # of Clamps | 12 |
| Bolt Size | M12 x 60 |
20″ ASA
| Flange I.D. (max) | 21.25 (539.8) |
| Flange O.D. | 27.50 (698.5) |
| Bolt Circle | 25.00 (635) |
| Bolt Hole | 1.25 (32) |
| # of Bolts | 20 |
| # of Clamps | None Required |
| Bolt Size | 18 x 3 1/2 |
30″ ASA
| Flange I.D. (max) | 32.125 (816) |
| Flange O.D. | 38.00 (965) |
| Bolt Circle | 36.25 (921) |
| Bolt Hole | 0.88 (22) |
| # of Bolts | 16 |
| # of Clamps | None Required |
| Bolt Size | 3/4-10 x 3 1/4 |
35″ ASA
| Flange I.D. (max) | 35.0 (889) |
| Flange O.D. | 41.75 (1060) |
| Bolt Circle | 38.50 (978) |
| Bolt Hole | 0.88 (22) |
| # of Bolts | 28 |
| # of Clamps | None Required |
| Bolt Size | 3/4-10 x 3 1/4 |
Legend
(*) All dimensions are in inches (mm).
(#) Thread size and bolt length are straight through – not tapped.
(+) Clamp clearance hole.
(++) Double claw clamps required.
