Bolting Dimensions for API Flanges

5000 lb. W.P.

Nominal Size InchesGasket API NumberNumber Of StudsStud Bolt Size Inches
2-1/16R2487/8 X 6
2-9/16R2781 X 6-1/2
3-1/8R3581-1/8 X 7-1/4
4-1/16R3981-1/4 X 8
5-1/8R4481-1/2 X 10
7-1/16R46121-3/8 X 10-3/4
9R50121-5/8 X 12
11R54121-7/8 X 13-3/4
13-5/8BX160161-5/8 X 12-1/2
16-3/4BX162161-7/8 X 14-1/2
18-3/4BX163202 X 17-1/2
21-1/4BX165242 X 18-3/4