Bolting Dimensions for API Flanges

20,000 lb. W.P.

Nominal Size InchesGasket API NumberNumber Of StudsStud Bolt Size Inches
1-13/16BX15181 X 7-1/2
2-1/16BX15281-1/8 X 8-1/4
2-9/16BX15381-1/4 X 9-1/4
3-1/16BX15481-3/8 X 10
4-1/16BX15581-3/4 X 12-1/4
7-1/16BX156162 X 17-1/2
9BX157162-1/2 X 22-1/2
11BX158162-3/4 X 23-3/4
13-5/8BX159203 X 30