Class 125SO Flange
Class 125SO Flanges
Class 125 SO (275 psi*)
Same as AWWA Table 4 Class E
Nom Size           Drilling  
OD Thickness  Dia at Base Bore LTH Bolt Circle Bolt Length Hole Dia # of Holes Weight
A  T E B L  C        
4 9.00 0.938 5.312 4.57 1.312 7.50 3.75 0.750 8 13
5 10.00 0.938 6.438 5.66 1.438 8.50 4.00 0.875 8 14
6 11.00 1.000 7.562 6.72 1.562 9.50 4.00 0.875 8 17
8 13.50 1.125 9.688 8.72 1.750 11.75 4.50 0.875 8 28
10 16.00 1.188 12.000 10.88 1.938 14.25 5.00 1.000 12 37
12 19.00 1.250 14.375 12.88 2.188 17.00 5.00 1.000 12 59
14 21.00 1.375 15.750 14.19 2.250 18.75 5.50 1.125 12 78
16 23.50 1.438 18.000 16.19 2.500 21.25 5.75 1.125 16 101
18 25.00 1.562 19.875 18.19 2.688 22.75 6.00 1.250 16 110
20 27.50 1.688 22.000 20.19 2.875 25.00 6.50 1.250 20 139
22 29.50 1.812 24.000 22.19 3.125 27.25 6.75 1.375 20 162
24 32.00 1.875 26.125 24.19 3.250 29.50 7.00 1.375 20 197
26 34.25 2.000 28.500 26.19 3.375 31.75 7.25 1.375 24 235
28 36.50 2.062 30.750 28.19 3.438 34.00 7.50 1.375 28 269
30 38.75 2.125 32.750 30.19 3.500 36.00 7.75 1.375 28 303
32 41.75 2.250 35.000 32.19 3.625 38.50 8.50 1.625 28 375
34 43.75 2.312 37.000 34.19 3.688 40.50 8.50 1.625 32 401
36 46.00 2.375 39.250 36.19 3.750 42.75 8.75 1.625 32 452
38 48.75 2.375 41.750 38.19 3.750 45.25 8.75 1.625 32 528
40 50.75 2.500 43.750 40.19 3.875 47.25 9.00 1.625 36 573
42 53.00 2.625 46.000 42.19 4.000 49.50 9.25 1.625 36 648
44 55.25 2.625 48.000 44.19 4.000 51.75 9.25 1.625 40 688
46 57.25 2.688 50.000 46.19 4.062 53.75 9.25 1.625 40 733
48 59.50 2.750 52.250 48.19 4.125 56.00 9.50 1.625 44 799
50 61.75 2.750 54.250 50.19 4.125 58.25 10.00 1.875 44 827
52 64.00 2.875 56.500 52.19 4.250 60.50 10.25 1.875 44 922
54 66.25 3.000 58.750 54.19 4.375 62.75 10.50 1.875 44 1024
60 73.00 3.125 65.250 60.19 4.500 69.25 11.00 1.875 52 1253
66 80.00 3.375 71.500 66.19 4.875 76.00 11.50 1.875 52 1623
72 86.50 3.500 78.500 72.19 5.000 82.50 11.75 1.875 60 1922
78 93.00 3.875 84.500 78.19 5.375 89.00 13.00 2.125 64 2279
84 99.75 3.875 90.500 84.19 5.375 95.50 13.00 2.125 64 2586
90 106.50 4.250 96.750 90.19 5.750 102.00 14.25 2.438 68 3061
96 113.25 4.250 102.750 96.19 5.750 108.50 14.25 2.438 68 3432
Dimensions are in inches.  Weights are in pounds.
Notes:  Commonly referred to as a class 150# in larger diameter.  Can be furnished with a raised face.  *Pressure ratings from AWWA table 4 Class E.  Pressure rating at atmopheric temperature is 275 psi.  These flanges have the same OD and drilling as ANSI/ASME B16.1 class 125 cast-iron flanges.  In sizes 24 in. and smaller, they also match ANSI/ASME B16.5 150-psi standard for steel flanges.  

Class 125 SO Flange PDF (for printing).