Bolting Dimensions for ANSI Flanges all sizes as per ANSI B16.5-1988

ANSI 400-lb Flanges

Nominal Pipe SizeDiameter of StudsNo.
Of
Studs
Stud Bolt LengthRing
Joint Gasket No.
Raised FaceRing Joint
InchesInchesInchesInches
1/21/2433R11
3/45/843-1/23-1/2R13
15/843-1/23-1/2R16
1-1/45/843-3/43-3/4R18
1-1/23/444-1/44-1/4R20
25/884-1/44-1/4R23
2-1/23/484-3/44-3/4R26
33/4855R31
3-1/27/885-1/25-1/2R34
47/885-1/25-1/2R37
57/885-3/45-3/4R41
67/81266R45
81126-3/46-3/4R49
101-1/8167-1/27-1/2R53
121-1/41688R57
141-1/4208-1/48-1/4R61
161-3/8208-3/48-3/4R65
181-3/82499R69
201-1/2249-1/29-1/2R73
221-5/8241010-1/2R81
241-3/42410-1/211R77