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G-14
ANSI Class 125. ANSI Class 250.
2-1/2 to 6-inch Cast Iron Flange Dimensions (as dened by ANSI standard B16.1)
ANSI Class 125
Nominal
Pipe Size
Flanges Drilling Bolting
Length of
Machine Bolts
Flange
Diameter
Flange
Thickness
Diameter of
Bolt Circle
Diameter of
Bolt Holes
Number of
Bolts
Diameter of
Bolts
A B D E F
2-1/2" 7" 11/16" 5-1/2" 3/4" 4 5/8" 2-1/2"
3" 7-1/2" 3/4" 6" 3/4" 4 5/8" 2-1/2"
4" 9" 15/16" 7-1/2" 3/4" 8 5/8" 3"
5" 10" 15/16" 8-1/2" 7/8" 8 3/4" 3"
6" 11" 1" 9-1/2" 7/8" 8 3/4" 3-1/4"
ANSI Class 250
Nominal
Pipe Size
Flanges Drilling Bolting
Length of
Machine Bolts
Flange
Diameter
Flange
Thickness
Diameter of
Raised Face
Diameter of
Bolt Circle
Diameter of
Bolt Holes
Number of
Bolts
Diameter of
Bolts
A B C D E F
2-1/2" 7-1/2" 1" 4-15/16" 5-7/8" 7/8" 8 3/4" 3-1/4"
3" 8-1/4" 1-1/8" 5-11/16" 6-5/8" 7/8" 8 3/4" 3-1/5"
4" 10" 1-1/4" 6-15/16" 7-7/8" 7/8" 8 3/4" 3-3/4"
5" 11" 1-3/8" 8-5/16" 9-1/4" 7/8" 8 3/4" 4"
6" 12-1/2" 1-7/16" 9-11/16" 10-5/8" 7/8" 12 3/4" 4"
Flanged Cast Iron Dimensions