Dimensions Blind Flanges & Stud Bolts ASME B16.5

Blind flange

Important  Information

NPS 1/2
Class 150 300 400 600 900 1500 2500
Diameter – D 90 95 95 95 120 120 135
Height – B 9.6 12.7 14.3 14.3 22.3 22.3 30.2
11.2 14.3 20.7 20.7 28.7 28.7 36.6
Diameter – G 35.1 35.1 35.1 35.1 35.1 35.1 35.1
Diameter – K 60.3 66.7 66.7 66.7 82.6 82.6 88.9
Bolt Holes 4 4 4 4 4 4 4
Diameter – L 15.9 15.9 15.9 15.9 22.2 22.2 22.2
Stud Bolts Diameter x Length
Diameter (in) 1/2 1/2 1/2 1/2 3/4 3/4 3/4
Length (mm) 55 65 75 75 110 110 120

NPS 3/4
CL 150 300 400 600 900 1500 2500
DIA
D
100 115 115 115 130 130 140
B 11.2 14.3 15.9 15.9 25.4 25.4 31.8
12.8 15.9 22.3 22.3 31.8 31.8 38.2
DIA
G
42.9 42.9 42.9 42.9 42.9 42.9 42.9
DIA
K
69.9 82.6 82.6 82.6 88.9 88.9 95
No. 4 4 4 4 4 4 4
DIA
L
15.9 19.1 19.1 19.1 22.2 22.2 22.2
Stud Bolts Diameter x Length
DIA
(in)
1/2 5/8 5/8 5/8 3/4 3/4 3/4
Len
mm
65 75 90 90 115 115 125

NPS 1
CL 150 300 400 600 900 1500 2500
DIA
D
110 125 125 125 150 150 160
B 12.7 15.9 17.5 17.5 28.6 28.6 35
14.3 17.5 23.9 23.9 35 35 41.4
DIA
G
50.8 50.8 50.8 50.8 50.8 50.8 50.8
DIA
K
79.4 88.9 88.9 88.9 101.6 101.6 107.4
No. 4 4 4 4 4 4 4
DIA
L
15.9 19.1 19.1 19.1 25.4 25.4 25.4
Stud Bolts Diameter x Length
DIA
(in)
1/2 5/8 5/8 5/8 7/8 7/8 7/8
Len
mm
65 75 90 90 125 125 140
NPS 1¼
CL 150 300 400 600 900 1500 2500
DIA
D
115 135 125 135 160 160 185
B 14.3 17.5 20.7 20.7 28.6 28.6 38.1
15.9 19.1 27.1 27.1 35 35 44.5
DIA
G
63.5 63.5 63.5 63.5 63.5 63.5 63.5
DIA
K
88.9 98.4 98.4 98.4 111.1 111.1 130
No. 4 4 4 4 4 4 4
DIA
L
15.9 19.1 19.1 19.1 25.4 25.4 28.6
Stud Bolts Diameter x Length
DIA
(in)
1/2 5/8 5/8 5/8 7/8 7/8 1
Len
mm
70 85 95 95 125 125 150
NPS 1½
CL 150 300 400 600 900 1500 2500
DIA
D
125 155 155 155 180 180 205
B 15.9 19.1 22.3 22.3 31.8 31.8 44.5
17.5 20.7 28.7 28.7 38.2 38.2 50.9
DIA
G
73 73 73 73 73 73 73
DIA
K
98.4 114.3 114.3 114.3 123.8 123.8 146
No. 4 4 4 4 4 4 4
DIA
L
15.9 22.2 22.2 22.2 28.6 28.6 31.8
Stud Bolts Diameter x Length
DIA
(in)
1/2 3/4 3/4 3/4 1 1 1⅛
Len
mm
70 90 110 110 140 140 170
NPS 2
CL 150 300 400 600 900 1500 2500
DIA
D
150 165 165 165 215 215 235
B 17.5 20.7 25.4 25.4 38.1 38.1 50.9
19.1 22.3 31.8 31.8 44.5 44.5 57.3
DIA
G
91.9 91.9 91.9 91.9 91.9 91.9 91.9
DIA
K
120.7 127 127 127 165.1 165.1 171.4
No. 4 8 8 8 8 8 8
DIA
L
19.1 19.1 19.1 19.1 25.4 25.4 28.6
Stud Bolts Diameter x Length
DIA
(in)
5/8 5/8 5/8 5/8 7/8 7/8 1
Len
mm
85 90 110 110 145 145 180

NPS 2½
CL 150 300 400 600 900 1500 2500
DIA
D
180 190 190 190 245 245 265
B 20.7 23.9 28.6 28.6 41.3 41.3 57.2
22.3 25.5 35 35 47.7 47.7 63.6
DIA
G
104.6 104.6 104.6 104.6 104.6 104.6 104.6
DIA
K
139.7 149.2 149.2 149.2 190.5 190.5 197
No. 4 8 8 8 8 8 8
DIA
L
19.1 22.2 22.2 22.2 28.6 28.6 31.8
Stud Bolts Diameter x Length
DIA
(in)
5/8 3/4 3/4 3/4 1 1 1⅛
Len
mm
90 100 120 120 160 160 195

NPS 3
CL 150 300 400 600 900 1500 2500
DIA
D
190 210 210 210 240 265 305
B 22.3 27 31.8 31.8 38.1 47.7 66.7
23.9 28.6 38.2 38.2 44.5 54.1 73.1
DIA
G
127 127 127 127 127 127 127
DIA
K
152.4 168.3 168.3 168.3 190.5 205 230
No. 4 8 8 8 8 8 8
DIA
L
19.1 22.2 22.2 22.2 25.4 31.8 34.9
Stud Bolts Diameter x Length
DIA
(in)
5/8 3/4 3/4 3/4 7/8 1⅛
Len
mm
90 110 125 125 145 180 220
NPS 3½
CL 150 300 400 600 900 1500 2500
DIA
D
215 230 230 230
B 22.3 28.6 35 35
23.9 30.2 41.4 41.4
DIA
G
139.7 139.7 139.7 139.7
DIA
K
177.8 184.2 184.2 184.2
No. 8 8 8 8
DIA
L
19.1 22.2 25.4 25.4
Stud Bolts Diameter x Length
DIA
(in)
5/8 3/4 7/8 7/8
Len
mm
90 110 140 140
NPS 4
CL 150 300 400 600 900 1500 2500
DIA
D
230 255 254 275 290 310 355
B 22.3 30.2 35 38.1 44.5 54 76.2
23.9 31.8 41.4 44.5 50.9 60.4 82.6
DIA
G
157.2 157.2 157.2 157.2 157.2 157.2 157.2
DIA
K
190.5 200 200 215.9 235 240 273
No. 8 8 8 8 8 8 8
DIA
L
19.1 22.2 25.4 25.4 31.8 34.9 41.3
Stud Bolts Diameter x Length
DIA
(in)
5/8 3/4 7/8 7/8 1⅛
Len
mm
90 115 140 145 170 195 255
NPS 6
CL 150 300 400 600 900 1500 2500
DIA
D
280 320 320 355 380 395 485
B 23.9 35 41.3 47.7 55.6 82.6 108
25.5 36.6 47.7 54.3 62 89 114.4
DIA
G
215.9 215.9 215.9 215.9 215.9 215.9 215.9
DIA
K
241.3 269.9 269.9 292.1 317.5 320 368
No. 8 12 12 12 12 12 8
DIA
L
22.2 22.2 25.4 28.6 31.8 38.1 54
Stud Bolts Diameter x Length
DIA
(in)
3/4 3/4 7/8 1 1⅛ 1⅜ 2
Len
mm
100 120 150 170 190 260 345
NPS 8
CL 150 300 400 600 900 1500 2500
DIA
D
345 380 381 420 470 485 550
B 27 39.7 47.7 55.6 63.5 92.1 127
28.6 41.3 54.1 62 69.9 98.5 133.4
DIA
G
269.9 269.7 269.7 269.7 269.7 269.7 269.7
DIA
K
298.5 330.2 330 349.2 393.7 395 438.1
No. 8 12 12 12 12 12 12
DIA
L
22.2 25.4 28.6 31.8 38.1 44.5 54
Stud Bolts Diameter x Length
DIA
(in)
3/4 7/8 1 1⅛ 1⅜ 1⅝ 2
Len
mm
110 140 170 190 220 290 380
NPS 10
CL 150 300 400 600 900 1500 2500
DIA
D
405 445 445 510 545 585 675
B 28.6 46.1 54 63.5 69.9 108 165
30.2 47.7 60.4 69.9 76.3 114.4 171.5
DIA
G
323.9 323.9 323.9 323.9 323.9 323.9 323.9
DIA
K
362 387.4 387.4 431.8 469.9 485 539.7
No. 12 16 16 16 16 12 12
DIA
L
25.4 28.6 31.8 34.9 38.1 50.8 66.7
Stud Bolts Diameter x Length
DIA
(in)
7/8 1 1⅛ 1⅜ 1⅞
Len
mm
115 160 190 215 235 335 490
NPS 12
CL 150 300 400 600 900 1500 2500
DIA
D
485 520 520 560 610 675 760
B 30.2 49.3 57.2 66.7 79.4 123.9 184.2
31.8 50.9 63.4 73.1 85.8 130.3 190.6
DIA
G
381 381 381 381 381 381 381
DIA
K
431.8 450.8 450.8 489 533.4 571.5 619.1
No. 12 16 16 20 20 16 12
DIA
L
25.4 31.8 34.9 34.9 38.1 54 73
Stud Bolts Diameter x Length
DIA
(in)
7/8 1⅛ 1⅜ 2
Len
mm
120 170 205 220 255 375 540
NPS 14
CL 150 300 400 600 900 1500 2500
DIA
D
535 585 585 605 640 750
B 33.4 52.4 60.4 69.9 85.8 133.4
35 54 66.8 76.3 92.2 139.8
DIA
G
412.8 412.8 412.8 412.8 412.8 412.8
DIA
K
476.3 514.4 514.4 527 558.8 635
No. 12 20 20 20 20 16
DIA
L
28.6 31.8 34.9 38.1 41.3 60.3
Stud Bolts Diameter x Length
DIA
(in)
1 1⅛ 1⅜
Len
mm
135 180 210 235 275 405
NPS 16
CL 150 300 400 600 900 1500 2500
DIA
D
595 650 650 685 705 825
B 35 55.6 63.5 76.2 88.9 146.1
36.6 57.2 69.9 82.6 95.3 152.5
DIA
G
469.9 469.9 469.9 469.9 469.9 469.9
DIA
K
539.8 571.5 571.5 603.2 616 705
No. 16 20 20 20 20 16
DIA
L
28.6 34.9 38.1 41.3 44.5 66.7
Stud Bolts Diameter x Length
DIA
(in)
1 1⅜ 1⅝
Len
mm
135 190 220 255 285 445
NPS 18
CL 150 300 400 600 900 1500 2500
DIA
D
635 710 710 745 785 915
B 38.1 58.8 66.7 82.6 101.6 162
39.7 60.4 73.1 89 108 168.4
DIA
G
533.4 533.4 533.4 533.4 533.4 533.4
DIA
K
577.9 628.6 628.6 654 685.8 775
No. 16 24 24 20 20 16
DIA
L
31.8 34.9 38.1 44.5 50.8 73
Stud Bolts Diameter x Length
DIA
(in)
1⅛ 1⅜ 1⅝ 1⅞
Len
mm
145 195 230 275 325 495
NPS 20
CL 150 300 400 600 900 1500 2500
DIA
D
700 775 775 815 855 985
B 41.3 62 69.9 88.9 108 180
42.9 63.6 76.3 95.3 114.4 184.2
DIA
G
584.2 584.2 584.2 584.2 584.2 584.2
DIA
K
635 685.8 685.8 723.9 749.3 831.8
No. 20 24 24 24 20 16
DIA
L
31.8 34.9 41.3 44.5 54 79.4
Stud Bolts Diameter x Length
DIA
(in)
1⅛ 1⅝ 2 3
Len
mm
160 205 240 285 350 540
NPS 24
CL 150 300 400 600 900 1500 2500
DIA
D
815 915 915 940 1040 1170
B 46.1 68.3 76.2 101.6 139.7 203.2
47.7 69.9 82.6 108 146.1 209.6
DIA
G
692.2 692.2 692.2 692.2 692.2 692.2
DIA
K
749.3 812.8 812.8 838.2 901.7 990.6
No. 20 24 24 24 20 16
DIA
L
34.9 41.3 47.6 50.8 66.7 92.1
Stud Bolts Diameter x Length
DIA
(in)
1⅞
Len
mm
170 230 265 330 440 615

Notes:

  • Dimensions are in millimeters unless otherwise indicated.
  • The length of the Stud Bolt does not include the height of the chamfers (points).
Measuring lengths of Stud Bolts and Hex bolts

Dimensional Tolerances of Blind Flanges ASME B16.5

Outside Diameter
≤ 24 = 1.6 mm | > 24 = ± 3.2 mm
Inside Diameter
not applicable
Diameter of Contact Face
1.6 mm Raised Face = ± 0.8 mm
6.35 mm Raised Face, Tongue & Groove / Male-Female = ± 0.4 mm
Outside Diameter of Hub
≤ 12 = + 2.4 mm / – 1.6 mm | ≥ 14 = ± 3.2 mm
Diameter of Counterbore
not applicable
Drilling
Bolt Circle = 1.6 mm | Bolt Hole Spacing = ± 0.8 mm
Eccentricity of Bolt Circle with Respect to Facing
≤ 2½ = 0.8 mm max. | ≥ 3 = 1.6 mm max.
Thickness
≤ 18 = + 3.2 mm / – 0 | ≥ 20 = + 4.8 mm / – 0
Length thru Hub
≤ 18 = + 3.2 mm / – 0.8 mm | ≥ 20 = + 4.8 mm / – 1.6 mm