ASME B16.5 Class 150 pipe flanges, NPS ½ to 24: dimensions, bolt circle, slip-on and blind — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/asme-b16-5-class-150-flanges/ (sheet CC BY 4.0) Basis: ASME B16.5 Class 150 dimensions as printed in manufacturer and distributor tables (Texas Flange, inch; cross-checked against a second table in mm); the standard itself is paywalled Catalog version: 2026-10-20 Sizes: see table below - Weld-neck, slip-on, blind, socket-weld and threaded flanges of one size and class share the flange OD, raised face, bolt circle, bolt holes and bolting; they differ in the hub, bore and length columns. Thickness is the minimum with the 1/16 in raised face included. - Raised face: 1/16 in (1.6 mm) high on Class 150 and 300. The flat plate is the printed thickness less that 1/16 in. - Holes are the bolt diameter plus 1/8 in, as the tables state; hole count and bolt diameter match the stud tables. Bolt holes straddle the vertical centreline in the files (the usual layout, not printed in the cited tables). - Files: for every NPS from ½ to 24, a blind flange and a slip-on flange at true size. The slip-on hub is drawn as a plain cylinder at the printed base diameter to the printed length: the tables do not print a hub taper, so none is drawn. The bore is the printed slip-on bore (pipe OD plus about 1 mm). - Not in the files: weld-neck flanges (hub taper and bevel are not printed; the base diameter and length are in the table), socket-weld and threaded flanges (their bore and thread columns are labelled ambiguously in the sources), weld bevels, fillet radii, the serrated finish of the face, and NPS 22 (printed by one source only). - Tables print inch; millimetres are the inch value × 25.4. The separate metric table of B16.5 rounds some sizes differently (for example NPS 1 Class 150 OD 110 mm against 4.25 in = 108 mm); the inch table is used here. - Class 300 is on its own page: asme-b16-5-class-300-flanges. Bolt pattern lookup for both classes: asme-b16-5-flange-bolt-patterns. NPS flange OD, in (mm) thickness incl. raised face, in (mm) raised-face dia, in (mm) bolt circle, in (mm) holes × hole dia, in bolt dia, in hub dia at base, in (mm) slip-on hub length, in weld-neck length, in slip-on bore, in weld-neck end OD, in 1/2 3.50 (88.9) 0.44 (11.1) 1.38 (34.9) 2.38 (60.3) 4 × 0.625 0.5 1.19 (30.2) 0.56 1.81 0.88 0.84 3/4 3.88 (98.4) 0.50 (12.7) 1.69 (42.9) 2.75 (69.8) 4 × 0.625 0.5 1.50 (38.1) 0.56 2.00 1.09 1.05 1 4.25 (107.9) 0.56 (14.3) 2.00 (50.8) 3.12 (79.4) 4 × 0.625 0.5 1.94 (49.2) 0.62 2.12 1.36 1.32 1-1/4 4.62 (117.5) 0.62 (15.9) 2.50 (63.5) 3.50 (88.9) 4 × 0.625 0.5 2.31 (58.7) 0.75 2.19 1.70 1.66 1-1/2 5.00 (127.0) 0.69 (17.5) 2.88 (73.0) 3.88 (98.4) 4 × 0.625 0.5 2.56 (65.1) 0.81 2.38 1.95 1.90 2 6.00 (152.4) 0.75 (19.0) 3.62 (92.1) 4.75 (120.6) 4 × 0.75 0.625 3.06 (77.8) 0.94 2.44 2.44 2.38 2-1/2 7.00 (177.8) 0.88 (22.2) 4.12 (104.8) 5.50 (139.7) 4 × 0.75 0.625 3.56 (90.5) 1.06 2.69 2.94 2.88 3 7.50 (190.5) 0.94 (23.8) 5.00 (127.0) 6.00 (152.4) 4 × 0.75 0.625 4.25 (107.9) 1.12 2.69 3.57 3.50 3-1/2 8.50 (215.9) 0.94 (23.8) 5.50 (139.7) 7.00 (177.8) 8 × 0.75 0.625 4.81 (122.2) 1.19 2.75 4.07 4.00 4 9.00 (228.6) 0.94 (23.8) 6.19 (157.2) 7.50 (190.5) 8 × 0.75 0.625 5.31 (134.9) 1.25 2.94 4.57 4.50 5 10.00 (254.0) 0.94 (23.8) 7.31 (185.7) 8.50 (215.9) 8 × 0.875 0.75 6.44 (163.5) 1.38 3.44 5.66 5.56 6 11.00 (279.4) 1.00 (25.4) 8.50 (215.9) 9.50 (241.3) 8 × 0.875 0.75 7.56 (192.1) 1.50 3.44 6.72 6.63 8 13.50 (342.9) 1.12 (28.6) 10.62 (269.9) 11.75 (298.4) 8 × 0.875 0.75 9.69 (246.1) 1.69 3.94 8.72 8.63 10 16.00 (406.4) 1.19 (30.2) 12.75 (323.8) 14.25 (361.9) 12 × 1 0.875 12.00 (304.8) 1.88 3.94 10.88 10.75 12 19.00 (482.6) 1.25 (31.8) 15.00 (381.0) 17.00 (431.8) 12 × 1 0.875 14.38 (365.1) 2.12 4.44 12.88 12.75 14 21.00 (533.4) 1.38 (34.9) 16.25 (412.8) 18.75 (476.2) 12 × 1.125 1 15.75 (400.0) 2.19 4.94 14.14 14.00 16 23.50 (596.9) 1.44 (36.5) 18.50 (469.9) 21.25 (539.8) 16 × 1.125 1 18.00 (457.2) 2.44 4.94 16.16 16.00 18 25.00 (635.0) 1.56 (39.7) 21.00 (533.4) 22.75 (577.9) 16 × 1.25 1.125 19.88 (504.8) 2.62 5.44 18.18 18.00 20 27.50 (698.5) 1.69 (42.9) 23.00 (584.2) 25.00 (635.0) 20 × 1.25 1.125 22.00 (558.8) 2.81 5.62 20.20 20.00 24 32.00 (812.8) 1.88 (47.6) 27.25 (692.1) 29.50 (749.3) 20 × 1.375 1.25 26.12 (663.6) 3.19 5.94 24.25 24.00 Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - Texas Flange: ANSI B16.5 Class 150 forged flange dimensions (inch) — web — Publisher's page; dimensions are facts — https://texasflange.com/products/flange-dims-weights/ansi-b16-5-forged-flanges/class-150/ - Wermac: Weld neck flanges ASME B16.5 Class 150 (inch) with stud bolt table — web — Publisher's page; dimensions are facts — https://wermac.org/flanges/dimensions_weldneck_in_asme-b16-5.html - Project Materials: Slip-on flange dimensions ASME B16.5 Class 150 and 300 (mm) — web — Publisher's page; dimensions are facts — https://blog.projectmaterials.com/flanges/slip-on-flange-dimensions-asme-ansi/ Free files (CC BY 4.0, Xem Studio; STEP + STL, 40 parts): https://xemstudio.com/files/hardware/asme-b16-5-class-150-flanges/index.json API: https://xemstudio.com/api/geometry?object=asme-b16-5-class-150-flanges