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2 inch class 150 flange: dimensions, bolt circle and drilling (ASME B16.5)

The 2 inch class 150 flange to ASME B16.5 is 6 in (152.4 mm) across, with 4 holes of 0.75 in (19.1 mm) on a 4.75 in (120.7 mm) bolt circle, for 5/8 in bolts; the pipe is 2.37 in (60.3 mm) outside. The holes straddle the centre lines, the first one 45° off, and the chord between neighbouring holes, which is the divider setting for stepping the drilling out, is 3.36 in (85.3 mm).

The 2 inch class 150 flange as the calculator draws it: the outline, the bore at the pipe outside diameter and the 4 holes.

Dimensions

Outside diameter6 in (152.4 mm)
Bolt circle (PCD)4.75 in (120.7 mm)
Number of holes4
Hole diameter0.75 in (19.1 mm)
Bolts5/8 in
Pipe outside diameter2.37 in (60.3 mm)
Angle between holes90°
First hole from the centre line45°
Chord between neighbouring holes3.36 in (85.3 mm)

Draw this flange: 1:1 template and DXF

Hole coordinates

From the centre of the flange, in in, with the first hole 45° off the horizontal axis and the others counter-clockwise, as the standards lay the drilling out.

Hole Angle x (in) y (in)
1 45° 1-11/16" 1-11/16"
2 135° -1-11/16" 1-11/16"
3 225° -1-11/16" -1-11/16"
4 315° 1-11/16" -1-11/16"

Questions

How many bolts does a %{size} %{class} flange have?
%{holes}, of %{bolt}, through holes of %{hole} on a %{circle} bolt circle.
What is the bolt circle of a %{size} %{class} flange?
%{circle}. The holes are %{angle}° apart, and the first one sits %{half}° off the centre line, so that two flanges mate in any symmetric position. The chord between neighbouring holes is %{chord}.
Can a %{size} %{class} flange be cut from plate?
As a plate flange, for low pressure: ducts, tanks, water lines. The outline and the drilling above are what the flange calculator draws, with the 1:1 template and the DXF for plasma or laser. A pressure flange to %{standard} is forged, with a hub and a raised face, and its thickness and facing come from the standard.