ANSI B16.5 FORGED FLANGES  Unit: mm
Class 2500 Normal Flanges
Nominal Pipe Size Outside Diam Diam of Base of Hub O.D. of Raised face Thick-ness  BORE LENGTH THRU HUB Diam of Hub of Bevel Radius of Filler Thread Length Drilling Bolting Approximate Weight Nominal Pipe Size
Stud Bolt Length Welding Neck Slip-on and Threaded  Lap Joint Blind
Welding Neck  Slip-on  Lap Joint Counter Bore Min.  Welding Neck  Slip-on Threaded  Lap Joint
Bolt Circle Diam Number of Holes   Diam of Holes Diam of Bolts (inch)  0.25 Raised Face Male female tongue-Groove Ring Joint
D X G t B1 B2 B3 B T1 T2 T3 A R Q Kg Ib Kg Ib Kg Ib Kg Ib
½ 133 42.9 35.1 30.2 See Note (1) To be Specified by purchaser.


















 22.4 22.9 23.6 73.2 39.6 39.6 21.3 3.0 28.4 88.9 4 22.4 ¾ 120.7 114.3 120.7 3.18 7.00 3.18 7.00 3.00 6.60 3.18 7.00 ½
¾  140 50.8 42.9 31.8 27.7 28.2 29.0 79.2 42.9 42.9 26.7 3.0 31.8 95.3 4 22.4 ¾ 127.0 120.7 127.0 4.08 9.00 4.08 9.00 3.63 8.00 4.54 10.00 ¾ 
1 159 57.2 50.8 35.1 34.5 35.1 35.8 88.9 47.8 47.8 33.5 3.0 35.1 108.0 4 25.4 7/8 139.7 133.4 139.7 5.45 12.00 5.44 12.00 4.99 11.00 5.44 12.00 1
1 ¼  184 73.2 63.5 38.1 43.2 43.7 44.5 95.3 52.3 52.3 42.2 4.8 38.1 130.0 4 28.4 1 152.4 146.1 152.4 9.07 20.00 8.16 18.00 7.26 16.00 8.16 18.00 1 ¼ 
1 ½  203 79.2 73.2 44.5 49.5 50.0 50.5 111.3 60.5 60.5 48.3 6.4 44.5 146.1 4 31.8 1 1/8 171.5 165.1 171.5 11.35 25.00 11.00 24.30 9.99 22.00 10.44 23.00 1 ½ 
2 235 95.3 91.9 50.8 62.0 62.5 63.5 127.0 69.9 69.9 60.5 7.9 50.8 171.5 8 28.4 1 177.8 171.5 177.8 19.70 42.00 17.25 38.00 16.80 37.00 17.71 39.00 2
2 ½  267 114.3 104.6 57.2 74.7 75.4 76.2 142.7 79.2 79.2 73.2 7.9 57.2 196.9 8 31.8 1 1/8 196.9 190.5 203.2 23.61 52.00 24.97 55.00 24.06 53.00 25.42 56.00 2 ½ 
3 305 133.4 127.0 66.5 90.7 91.4 92.2 168.1 91.9 91.9 88.9 9.7 63.5 228.6 8 35.1 1 ¼ 222.3 215.9 228.6 42.68 94.00 37.68 83.00 36.32 80.00 39.04 86.00 3
4 356 165.1 157.2 76.2 116.1 116.8 117.6 190.5 108.0 108.0 114.3 11.2 69.9 273.1 8 41.1 1 ½ 254.0 247.7 260.4 64.00 141.00 58.00 127.90 54.48 120.00 60.38 133.00 4
5 419 203.2 185.7 91.9 143.8 144.5 144.5 228.6 130.0 130.0 141.2 11.2 76.2 323.9 8 47.8 1 ¾ 298.5 292.1 311.2 110.68 244.00 95.25 210.00 92.53 204.00 101.15 223.00 5
6 483 235.0 215.9 108.0 170.7 171.5 171.5 273.1 152.4 152.4 168.4 12.7 82.6 368.3 8 53.8 2 342.9 336.6 355.6 176.46 378.00 146.51 323.00 143.01 315.30 156.63 345.30 6
8 552 304.8 269.7 127.0 221.5 222.3 222.3 317.5 177.8 177.8 219.2 12.7 95.3 438.2 12 53.8 2 381.0 374.7 393.7 261.27 576.00 219.99 485.00 213.38 470.40 240.62 530.50 8
10 673 374.7 323.9 165.1 276.4 277.4 276.4 419.1 228.6 228.6 273.1 12.7 108.0 539.8 12 66.5 2 ½ 489.0 482.6 508.0 484.43 1068.00 419.57 925.00 408.60 900.80 465.36 1026.00 10
12 762 441.5 381.0 184.2 327.2 328.2 328.7 463.6 254.0 254.0 323.9 12.7 120.7 619.3 12 73.2 2 ¾ 539.8 533.4 558.8 692.35 1526.30 590.20 1301.00 572.95 1263.00 664.06 1464.00 12
Notes:
(1) For the inside diameter of pipes (corresponding to Bore (B1) of welding Neck Flanges), refer to page 56.
(2) Class 2500 flanges except lap Joint will be furnished with 0.25" (6.35mm) raised face, which is not included in Thickness (t)
 and length through Hub (T1), (T2)
(3) For Slip-on, Threaded and lap joint Flanges, the hubs can be shaped either vertical from base to top or tapered within the limits of 7 degrees.
(4) Blind Flanges may be made with the same hub as that used for slip-on Flanges or without hub.
(5) The gasket surface and backside (bearing surface for bolting) are made parallel within 1 degree, to accomplish parallelism.
spot facing is carried out according to MSS SP-9 without reducing thickness(t).
(6) Class 2500 Slip-on Flanges are not covered by ANSI B16.5 Slip-on Flanges are at the manufacturers option