Bolting Dimensions for API Flanges

15,000 lb. W.P.

Nominal Size InchesGasket API NumberNumber Of StudsStud Bolt Size Inches
1-13/16BX15187/8 X 5-1/2
2-1/16BX15287/8 X 6
2-9/16BX15381 X 6-3/4
3-1/16BX15481-1/8 X 7-1/2
4-1/16BX15581-3/8 X 9-1/4
5-1/8BX169121-1/2 X 11-1/2
7-1/16BX156161-1/2 X 12-3/4
9BX157161-7/8 X 15-3/4
11BX158202 X 19-1/4
13-5/8BX159202-1/4 X 21-1/4
18-3/4BX164203 X 26-3/4