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DN 50 PN 10 flange: dimensions, bolt circle and drilling (EN 1092-1)

The DN 50 PN 10 flange to EN 1092-1 is 165 mm (6.5 in) across, with 4 holes of 18 mm (0.71 in) on a 125 mm (4.92 in) bolt circle, for M16 bolts; the pipe is 60.3 mm (2.37 in) 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 88.4 mm (3.48 in).

The DN 50 PN 10 flange as the calculator draws it: the outline, the bore at the pipe outside diameter and the 4 holes.

Dimensions

Outside diameter165 mm (6.5 in)
Bolt circle (PCD)125 mm (4.92 in)
Number of holes4
Hole diameter18 mm (0.71 in)
BoltsM16
Pipe outside diameter60.3 mm (2.37 in)
Angle between holes90°
First hole from the centre line45°
Chord between neighbouring holes88.4 mm (3.48 in)

Draw this flange: 1:1 template and DXF

Hole coordinates

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

Hole Angle x (mm) y (mm)
1 45° 43.8 43.8
2 135° -43.8 43.8
3 225° -43.8 -43.8
4 315° 43.8 -43.8

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.