Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Flanges - ASME/ANSI B16.5 Flanges and Bolt Dimensions - Class 150 to 2500

Diameters and bolt circles for standard ASME B16.5 flanges - 1/4 to 24 inches - Class 150 to 2500.

Flange dimensions are determined by the pipe size and the pressure class required for the application. Flanges are standardized according publications from organizations like ASME, MSS, API and others.

Ansi B16.5 Welded Neck Raised Face Flange

ASME/ANSI B16.5 provides

  • weld neck
  • slip-on
  • socket weld
  • threaded
  • lap joint
  • blind

flange dimensions for pipes ranging 1/2" to 24" - in classes ranging 150 to 2500. Note that the ratings are in steps with terminology like ASME class xxx or API xxxx.

In general you need to specify the schedule (thickness) of the connected pipe when it is being butt welded to the flange. Socket welded and threaded connections is unaffected by wall thickness and should only require the OD.

ASME/ANSI B16.5 Flanges and Bolt Dimensions - Class 150
Nominal Pipe Size
NPS
(inches)		Class 150
Diameter of
Flange
(inches)		No.
of
Bolts		Diameter of
Bolts
(inches)		Diameter of
Bolt Holes
(inches)		Bolt
Circle
(inches)
1/4 3-3/8 4 1/2 0.62 2-1/4
1/2 3-1/2 4 1/2 0.62 2-3/8
3/4 3-7/8 4 1/2 0.62 2-3/4
1 4-1/4 4 1/2 0.62 3-1/8
1-1/4 4-5/8 4 1/2 0.62 3-1/2
1-1/2 5 4 1/2 0.62 3-7/8
2 6 4 5/8 0.75 4-3/4
2-1/2 7 4 5/8 0.75 5-1/2
3 7-1/2 4 5/8 0.75 6
3-1/2 8-1/2 8 5/8 0.75 7
4 9 8 5/8 0.75 7-1/2
5 10 8 3/4 0.88 8-1/2
6 11 8 3/4 0.88 9-1/2
8 13-1/2 8 3/4 0.88 11-3/4
10 16 12 7/8 1 14-1/4
12 19 12 7/8 1 17
14 21 12 1 1.12 18-3/4
16 23-1/2 16 1 1.12 21-1/4
18 25 16 1-1/8 1.25 22-3/4
20 27-1/2 20 1-1/8 1.25 25
24 32 20 1-1/4 1.38 29-1/2
  • 1 inch = 25.4 mm
ASME/ANSI B16.5 Flanges and Bolt Dimensions - Class 300
Nominal Pipe Size
NPS
(inches)		Class 300
Diameter of
Flange
(inches)		No.
of
Bolts		Diameter of
Bolts
(inches)		Diameter of
Bolt Holes
(inches)		Bolt
Circle
(inches)
1/4 3-3/8 4 1/2 0.62 2-1/4
1/2 3-3/4 4 1/2 0.62 2-5/8
3/4 4-5/8 4 5/8 0.75 3-1/4
1 4-7/8 4 5/8 0.75 3-1/2
1-1/4 5-1/4 4 5/8 0.75 3-7/8
1-1/2 6-1/8 4 3/4 0.88 4-1/2
2 6-1/2 8 5/8 0.75 5
2-1/2 7-1/2 8 3/4 0.88 5-7/8
3 8-1/4 8 3/4 0.88 6-5/8
3-1/2 9 8 3/4 0.88 7-1/4
4 10 8 3/4 0.88 7-7/8
5 11 8 3/4 0.88 9-1/4
6 12-1/2 12 3/4 0.88 10-5/8
8 15 12 7/8 1 13
10 17-1/2 16 1 1.12 15-1/4
12 20-1/2 16 1-1/8 1.25 17-3/4
14 23 20 1-1/8 1.25 20-1/4
16 25-1/2 20 1-1/4 1.38 22-1/2
18 28 24 1-1/4 1.38 24-3/4
20 30-1/2 24 1-1/4 1.38 27
24 36 24 1-1/2 1.62 32
ASME/ANSI B16.5 Flanges and Bolt Dimensions - Class 400

Nominal Pipe Size
NPS
(inches)

Class 400
Diameter of
Flange
(inches)		No.
of
Bolts		Diameter of
Bolts
(inches)		Diameter of
Bolt Holes
(inches)		Bolt
Circle
(inches)
1/4 3-3/8 4 1/2 0.62 2-1/4
1/2 3-3/4 4 1/2 0.62 2-5/8
3/4 4-5/8 4 5/8 0.75 3-1/4
1 4-7/8 4 5/8 0.75 3-1/2
1-1/4 5-1/4 4 5/8 0.75 3-7/8
1-1/2 6-1/8 4 3/4 0.88 4-1/2
2 6-1/2 8 5/8 0.75 5
2-1/2 7-1/2 8 3/4 0.88 5-7/8
3 8-1/4 8 3/4 0.88 6-5/8
3-1/2 9 8 7/8 1 7-1/4
4 10 8 7/8 1 7-7/8
5 11 8 7/8 1 9-1/4
6 12-1/2 12 7/8 1 10-5/8
8 15 12 1 1.12 13
10 17-1/2 16 1-1/8 1.25 15-1/4
12 20-1/2 16 1-1/4 1.38 17-3/4
14 23 20 1-1/4 1.38 20-1/4
16 25-1/2 20 1-3/8 1.5 22-1/2
18 28 24 1-3/8 1.5 24-3/4
20 30-1/2 24 1-1/2 1.62 27
24 36 24 1-3/4 1.88 32
ASME/ANSI B16.5 Flanges and Bolt Dimensions - Class 600
Nominal Pipe Size
NPS
(inches)		Class 600
Diameter of
Flange
(inches)		No.
of
Bolts		Diameter of
Bolts
(inches)		Diameter of
Bolt Holes
(inches)		Bolt
Circle
(inches)
1/4 3-3/8 4 1/2 0.62 2-1/4
1/2 3-3/4 4 1/2 0.62 2-5/8
3/4 4-5/8 4 5/8 0.75 3-1/4
1 4-7/8 4 5/8 0.75 3-1/2
1-1/4 5-1/4 4 5/8 0.75 3-7/8
1-1/2 6-1/8 4 3/4 0.88 4-1/2
2 6-1/2 8 5/8 0.75 5
2-1/2 7-1/2 8 3/4 0.88 5-7/8
3 8-1/4 8 3/4 0.88 6-5/8
3-1/2 9 8 7/8 1 7-1/4
4 10-3/4 8 7/8 1 8-1/2
5 13 8 1 1.12 10-1/2
6 14 12 1 1.12 11-1/2
8 16-1/2 12 1-1/8 1.25 13-3/4
10 20 16 1-1/4 1.38 17
12 22 20 1-1/4 1.38 19-1/4
14 23-3/4 20 1-3/8 1.5 20-3/4
16 27 20 1-1/2 1.62 23-3/4
18 29-1/4 20 1-5/8 1.75 25-3/4
20 32 24 1-5/8 1.75 28-1/2
24 37 24 1-7/8 2 33
ASME/ANSI B16.5 Flanges and Bolt Dimensions - Class 900
Nominal Pipe Size
NPS
(inches)		Class 900
Diameter of
Flange
(inches)		No.
of
Bolts		Diameter of
Bolts
(inches)		Diameter of
Bolt Holes
(inches)		Bolt
Circle
(inches)
1/2 4-3/4 4 3/4 0.88 3-1/4
3/4 5-1/8 4 3/4 0.88 3-1/2
1 5-7/8 4 7/8 1 4
1-1/4 6-1/4 4 7/8 1 4-3/8
1-1/2 7 4 1 1.12 4-7/8
2 8-1/2 8 7/8 1 6-1/2
2-1/2 9-5/8 8 1 1.12 7-1/2
3 9-1/2 8 7/8 1 7-1/2
4 11-1/2 8 1-1/8 1.25 9-1/4
5 13-3/4 8 1-1/4 1.38 11
6 15 12 1-1/8 1.25 12-1/2
8 18-1/2 12 1-3/8 1.5 15-1/2
10 21-1/2 16 1-3/8 1.5 18-1/2
12 24 20 1-3/8 1.5 21
14 25-1/4 20 1-1/2 1.62 22
16 27-3/4 20 1-5/8 1.75 24-1/2
18 31 20 1-7/8 2 27
20 33-3/4 20 2 2.12 29-1/2
24 41 20 2-1/2 2.62 35-1/2
ASME/ANSI B16.5 Flanges and Bolt Dimensions - Class 1500
Nominal Pipe Size
NPS
(inches)		Class 1500
Diameter of
Flange
(inches)		No.
of
Bolts		Diameter of
Bolts
(inches)		Diameter of
Bolt Holes
(inches)		Bolt
Circle
(inches)
1/2 4-3/4 4 3/4 0.88 3-1/4
3/4 5-1/8 4 3/4 0.88 3-1/2
1 5-7/8 4 7/8 1 4
1-1/4 6-1/4 4 7/8 1 4-3/8
1-1/2 7 4 1 1.12 4-7/8
2 8-1/2 8 7/8 1 6-1/2
2-1/2 9-5/8 8 1 1.12 7-1/2
3 10-1/2 8 1-1/8 1.25 8
4 12-1/4 8 1-1/4 1.38 9-1/2
5 14-3/4 8 1-1/2 1.62 11-1/2
6 15-1/2 12 1-3/8 1.5 12-1/2
8 19 12 1-5/8 1.75 15-1/2
10 23 12 1-7/8 2 19
12 26-1/2 16 2 2.12 22-1/2
14 29-1/2 16 2-1/4 2.38 25
16 32-1/2 16 2-1/2 2.62 27-3/4
18 36 16 2-3/4 2.88 30-1/2
20 38-3/4 16 3 3.12 32-3/4
24 46 16 3-1/2 3.62 39
ASME/ANSI B16.5 Flanges and Bolt Dimensions - Class 2500
Nominal Pipe Size
NPS
(inches)		Class 2500
Diameter of
Flange
(inches)		No.
of
Bolts		Diameter of
Bolts
(inches)		Diameter of
Bolt Holes
(inches)		Bolt
Circle
(inches)
1/2 5-1/4 4 3/4 0.88 3-1/2
3/4 5-1/2 4 3/4 0.88 3-3/4
1 6-1/4 4 7/8 1 4-1/4
1-1/4 7-1/4 4 1 1.12 5-1/8
1-1/2 8 4 1-1/8 1.25 5-3/4
2 9-1/4 8 1 1.12 6-3/4
2-1/2 10-1/2 8 1-1/8 1.25 7-3/4
3 12 8 1-1/4 1.38 9
4 14 8 1-1/2 1.62 10-3/4
5 16-1/2 8 1-3/4 1.88 12-3/4
6 19 8 2 2.12 14-1/2
8 21-3/4 12 2 2.12 17-1/4
10 26-1/2 12 2-1/2 2.62 21-1/4
12 30 12 2-3/4 2.88 24-3/8

Engineering ToolBox Sketchup Extension - flanges

Insert flanges to your Sketchup model with the Engineering ToolBox Sketchup Extension

Related Topics

Related Documents

Search

Search is the most efficient way to navigate the Engineering ToolBox.

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

Translate this Page

Translate this page to Your Own Language .

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

We use a third-party to provide monetization technologies for our site. You can review their privacy and cookie policy here.

You can change your privacy settings by clicking the following button: .

Citation

This page can be cited as

  • The Engineering ToolBox (2003). Flanges - ASME/ANSI B16.5 Flanges and Bolt Dimensions - Class 150 to 2500. [online] Available at: https://www.engineeringtoolbox.com/flanges-bolts-dimensions-d_464.html [Accessed Day Month Year].

Modify the access date according your visit.

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter

















































4.19.9

.