Weld Neck Flange Bore Chart

Nom pipe
Size
OD NOMINAL BORE
Sch10 Sch20 Sch30 STD Wall Sch40 Sch60 EXT Hvy Sch80 Sch100 Sch120 Sch140 Sch160 XX Hvy
1/2 0.840 0.674 0.622 0.622 0.546 0.546 0.464 0.252
3/4 1.050 0.884 0.824 0.824 0.742 0.742 0.612 0.434
1 1.315 1.097 1.049 1.049 0.957 0.957 0.815 0.599
1 1/4 1.660 1.442 1.380 1.380 1.278 1.278 1.160 0.896
1 1/2 1.900 1.682 1.610 1.610 1.500 1.500 1.338 1.100
2 2.375 2.157 2.067 2.067 1.939 1.939 1.687 1.503
2 1/2 2.875 2.635 2.469 2.469 2.323 2.323 2.125 1.771
3 3.500 3.260 3.068 3.068 2.900 2.900 2.624 2.300
3 1/2 4.000 3.760 3.548 3.548 3.364 3.364 2.728
4 4.500 4.260 4.026 4.026 3.826 3.826 3.624 3.438 3.152
5 5.563 5.295 5.047 5.047 4.813 4.813 4.563 4.313 4.063
6 6.625 6.357 6.065 6.065 5.761 5.761 5.501 5.187 4.897
8 8.625 8.329 8.125 8.071 7.981 7.981 7.813 7.625 7.625 7.437 7.187 7.001 6.813 6.875
10 10.750 10.420 10.250 10.136 10.020 10.020 9.750 9.750 9.562 9.312 9.062 8.750 8.500 8.750
12 12.750 12.390 12.250 12.090 12.000 11.938 11.626 11.750 11.374 11.062 10.750 10.500 10.126 10.750
14 14.000 13.500 13.376 13.250 13.250 13.124 12.812 13.000 12.500 12.124 11.812 11.500 11.188
16 16.000 15.500 15.376 15.250 15.250 15.000 14.688 15.000 14.312 13.938 13.562 13.124 12.812
18 18.000 17.500 17.376 17.124 17.250 16.876 16.500 17.000 16.124 15.688 15.250 14.876 14.438
20 20.000 19.500 19.250 19.000 19.250 18.812 18.376 19.000 17.938 17.438 17.000 16.500 16.062
22 22.000 21.500 21.250 21.000
24 24.000 23.500 23.250 22.876 23.250 22.624 22.062 23.000 21.562 20.938 20.376 19.876 19.312
26 26.000 25.250 25.000
30 30.000 29.376 29.000 28.750 29.250 29.000
36 36.000 35.376 35.000 34.750 35.250 34.500 35.000
40 40.000 39.250 39.000
42 42.000 41.250 41.000
48 48.000 47.250 47.000

dimensions are in inches
(1) Source: ANSI B36.10
(2) These dimensions are the same for inside pipe diameter. ALWAYS specify bore when ordering
(3) Other type, sizes, and thicknesses of flanges can be provided to meet application
(4) Stocked and manufactured in carbon steel, stainless steel, adn a variety of other metals and alloys
(5) Flange Wall Thickness

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