Reference Data

FLANGE COMPARISON TABLES

The following tables are based on the British Standards stated. They are intended as a guide and for further details of flange
thickness and pressure/temperature ratings particularly, please refer to the standards.

Flange Dimensions

D : - Flange Diameter
P : - Bolt Hole Pitch Circle Diameter
d : - Bolt Hole Diameter
t : - Flange Thickness Including Raised Face
R : - Raised Face Diameter
f : - Raised Face Height
N : - Number of Bolt Holes

The Flange thickness given is for Carbon Steel Flanges.

Cast Iron Flanges are generally thicker.

NOTES:

1) Class 125 and class 250 are for cast iron flanges and have the same dimensions as classes 150 and 300 respectively.
2) Abbreviations: FF flat faced, RF raised face, RJ ring joint (facing).
3) BS4504 dimensions are based on mm and converted to the nearest 1/16 in.
ASME B16.5 and BS 10 dimensions are based on inches and converted to mm.

Flange Comparison Tables

Sizes	Printable PDF's
1/2” & 15mm	Print
3/4" & 20mm	Print
1" & 25mm	Print
1 1/4" & 32mm	Print
1 1/2 ” & 40mm	Print
2" & 50mm	Print
2 1/2” & 65mm	Print
3" & 80mm	Print
4" & 100mm	Print
5" & 125mm	Print
6" & 150mm	Print
8" & 200mm	Print
10" & 250mm	Print
12" & 300mm	Print
14" & 350mm	Print
15" & 400mm	Print
18" & 450mm	Print
20" & 500mm	Print
24" & 600mm	Print

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