Flange Size Chart In MM

Selecting the correct flange size is vital for efficient piping systems. In our article, we delve into the millimeter-based flange size chart, a widely used industry standard. We’ll cover flange types, standard sizes, and accurate measurement methods, empowering engineers and DIYers alike to choose the optimal flange size for their needs. With this knowledge, you can avoid leaks and malfunctions, ensuring the smooth operation of your piping system.

Flange Size Chart

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN1495674M1214
AS 2129Table C95674M1214
Table D95674M1214
Table E95674M1214
Table F95674M1214
Table H114834M1617
Table J114834M1617
ANSI B16.5ANSI 150896041316
ANSI 300956741316
ANSI 600956741316
ANSI 9001218341922
ANSI 15001218341922
ISO 7005 (DIN)PN680554M1011

20mm (3/4″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN14100734M1214
AS 2129Table C100734M1214
Table D100734M1214
Table E100734M1214
Table F100734M1214
Table H115834M1218
Table J115834M1218
ANSI B16.5ANSI 150987041316
ANSI 3001178341619
ANSI 6001178341619
ANSI 9001308941922
ANSI 15001308941922
ISO 7005 (DIN)PN690654M1011

25mm (1″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN14115834M1214
AS 2129Table C115834M1214
Table D115834M1214
Table E115834M1214
Table F120874M1618
Table H120874M1618
Table J120874M1618
ANSI B16.5ANSI 1501107941316
ANSI 3001258941619
ANSI 6001258941619
ANSI 90010242225
ANSI 150010242225
ISO 7005 (DIN)PN6100784M1011

32mm (1 1/4″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN14120874M1214
AS 2129Table C120874M1214
Table D120874M1214
Table E120874M1214
Table F135984M1618
Table H135984M1618
Table J135984M1618
ANSI B16.5ANSI 1501178941316
ANSI 3001339841619
ANSI 6001339841619
ANSI 90015911142225
ANSI 150015911142225
ISO 7005 (DIN)PN6120904M1214

40mm (1 1/2″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN14135984M1214
AS 2129Table C135984M1214
Table D135984M1214
Table E135984M1214
Table F1401054M1618
Table H1401054M1618
Table J1401054M1618
ANSI B16.5ANSI 1501279841316
ANSI 30015611441922
ANSI 60015611441922
ANSI 90017812442529
ANSI 150017812442529
ISO 7005 (DIN)PN61301004M1214

50mm (2″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN141501144M1618
AS 2129Table C1501144M1618
Table D1501144M1618
Table E1501144M1618
Table F1651274M1618
Table H1651274M1618
Table J1651274M2022
ANSI B16.5ANSI 15015212141619
ANSI 30016512781619
ANSI 60016512781619
ANSI 90021616582225
ANSI 150021616582225
ISO 7005 (DIN)PN61401104M1214
*When made from cast or ductile iron the OD is 155mm.

65mm (2 1/2″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN141651274M1618
AS 2129Table C1651274M1618
Table D1651274M1618
Table E1651274M1618
Table F1851468M1618
Table H1851468M1618
Table J1851468M2022
ANSI B16.5ANSI 15017814041619
ANSI 30019114981922
ANSI 60019114981922
ANSI 90024419182225
ANSI 150024419182529
ISO 7005 (DIN)PN61601304M1214

80mm (3″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN141851464M1618
AS 2129Table C1851464M1618
Table D1851464M1618
Table E1851464M1618
Table F2051658M1618
Table H2051658M1618
Table J2051658M2022
ANSI B16.5ANSI 15019115241619
ANSI 30021016881922
ANSI 60021016881922
ANSI 90024119282225
ANSI 150026720382932
ISO 7005 (DIN)PN61901504M1618

100mm (4″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN142151784M1618
AS 2129Table C2151784M1618
Table D2151784M1618
Table E2151788M1618
Table F2301918M1618
Table H2301918M1618
Table J2301918M2022
ANSI B16.5ANSI 15022919181619
ANSI 30025420081922
ANSI 60027321682225
ANSI 90029223582932
ANSI 150031124183235
ISO 7005 (DIN)PN62101704M1618

125mm (5″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN142552108M1618
AS 2129Table C2552108M1618
Table D2552108M1618
Table E2552108M1618
Table F2802358M2022
Table H2802358M2022
Table J2802358M2426
ANSI B16.5ANSI 15025421681922
ANSI 30027923581922
ANSI 60033026782529
ANSI 90034927983235
ANSI 150037529283841
ISO 7005 (DIN)PN62402008M1618

150mm (6″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN142802358M1618
AS 2129Table C2802358M1618
Table D2802358M1618
Table E2802358M2022
Table F30526012M2022
Table H30526012M2022
Table J30526012M2426
ANSI B16.5ANSI 15027924181922
ANSI 300318270121922
ANSI 600356292122529
ANSI 900381318122932
ANSI 1500394318123538
ISO 7005 (DIN)PN62652258M1618

200mm (8″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN143352928M1618
AS 2129Table C3352928M1618
Table D3352928M1618
Table E3352928M2022
Table F37032412M2022
Table H37032412M2022
Table J37032412M2426
ANSI B16.5ANSI 15034329881922
ANSI 300381330121922
ANSI 600419349122932
ANSI 900470394123538
ANSI 1500483394124144
ISO 7005 (DIN)PN63202808M1618

250mm (10″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN144053568M2022
AS 2129Table C4053568M2022
Table D4053568M2022
Table E40535612M2022
Table F43038112M2426
Table H43038112M2426
Table J43038112M2730
ANSI B16.5ANSI 150406362122225
ANSI 300445387162529
ANSI 600508432163235
ANSI 900546470163538
ANSI 1500584483124151
ISO 7005 (DIN)PN637533512M1618

300mm (12″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN1445540612M2022
AS 2129Table C45540612M2022
Table D45540612M2022
Table E45540612M2426
Table F49043816M2426
Table H49043816M2426
Table J49043816M2730
ANSI B16.5ANSI 150483432122225
ANSI 300521451162932
ANSI 600559489203235
ANSI 900610533203538
ANSI 1500673571165154
ISO 7005 (DIN)PN644039512M2022

350mm (14″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN1452547012M2426
AS 2129Table C52547012M2426
Table D52547012M2426
Table E52547012M2426
Table F55049516M2730
Table H55049516M2730
Table J55049516M3032
ANSI B16.5ANSI 150533476122529
ANSI 300584514202932
ANSI 600603527203841
ANSI 900641559203841
ANSI 1500749635165760
ISO 7005 (DIN)PN649044512M2022

400mm (16″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN1458052112M2426
AS 2129Table C58052112M2426
Table D58052112M2426
Table E58052112M2426
Table F61055220M2730
Table H61055220M2730
Table J61055220M3033
ANSI B16.5ANSI 150597540161″ (M24)29
ANSI 300648572201-1/4″ (M30)35
ANSI 600686603201-1/2″ (M36)41
ANSI 900705616201-5/8″ (M42)44
ANSI 1500826705162-1/2″ (M64)67
ISO 7005 (DIN)PN654049516M2022

450mm (18″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN14 Flange64058412M2426
PN16 Flange64058412M2426
PN21 Flange67561020M3033
PN35 Flange67551020M3033
AS 2129Table C Flange64058412M2426
Table D Flange64058412M2426
Table E Flange64058416M2426
Table F Flange67561020M3033
Table H Flange67561020M3033
Table J Flange67561020M3336
ANSI B16.5ANSI 150 Flange635578161-1/8″ (M27)32
ANSI 300 Flange711629241-1/4″ (M30)35
ANSI 600 Flange743654201-5/8″ (M42)44
ANSI 900 Flange787686201-7/8″ (M48)51
ANSI 1500 Flange914775162-3/4″ (M72)73
ISO 7005 (DIN)PN6 Flange59555016M2022
PN10 Flange61556520M2426
PN16 Flange64058520M2730
PN20 Flange63557816M3032.5
PN25 Flange
PN40 Flange

500mm (20″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN14 Flange70564116M2426
PN16 Flange70564116M2426
PN21 Flange73567324M3033
PN35 Flange73567324M3033
AS 2129Table C Flange70564116M2426
Table D Flange70564116M2426
Table E Flange70564116M2426
Table F Flange73567324M3033
Table H Flange73567324M3033
Table J Flange73567324M3336
ANSI B16.5ANSI 150 Flange699635201-1/8″ (M27)32
ANSI 300 Flange775686241-1/4″ (M30)35
ANSI 600 Flange813724241-5/8″ (M42)44
ANSI 900 Flange857749202″ (M48)54
ANSI 1500 Flange984832163″ (M80)79
ISO 7005 (DIN)PN6 Flange64560020M2022
PN10 Flange67062020M2426
PN16 Flange71565020M3033
PN20 Flange70063520M3032.5
PN25 Flange
PN40 Flange

600mm (24″)

StandardClassDiameterBolt Circle DiameterNumber of BoltsBolt SizeDiameter of Bolt Hole
AS 4087PN14 Flanges82575616M2730
PN16 Flanges82575616M2730
PN21 Flanges85078124M3336
PN35 Flanges75078124M3336
AS 2129Table C Flanges82575616M2730
Table D Flanges82575616M2730
Table E Flanges82575616M3033
Table F Flanges85078124M3336
Table H Flanges85078124M3336
Table J Flanges85078124M3639
ANSI B16.5ANSI 150 Flanges813749201-1/4″ (M30)35
ANSI 300 Flanges914813241-1/2″ (M36)41
ANSI 600 Flanges940838241-7/8″ (M48)51
ANSI 900 Flanges1041902202-1/2″ (M64)67
ANSI 1500 Flanges1168991163-1/2″ (M90)92
ISO 7005 (DIN)PN6 Flanges75570520M2426
PN10 Flanges78072520M2730
PN16 Flanges84077020M3336
PN20 Flanges815749.520M3336
PN25 Flanges
PN40 Flanges

What Are Flanges

If you’re unfamiliar with the term “flanges,” don’t worry – you’re not alone! In basic terms, flanges are a type of connecting component used in piping systems. They are typically used to join two pipes or pieces of equipment together, such as valves, pumps, or vessels. Flanges come in a variety of shapes and sizes, but all of them share a common feature: a flat, circular plane that can be bolted to another matching plane with a similar flange.

This creates a secure connection between the two pieces of equipment, allowing for the transfer of fluids or gases without any leaks or spills. Flanges are an essential component of many industrial processes, including oil and gas production, chemical manufacturing, and water treatment. By using flanges, engineers and technicians can ensure that their piping systems operate safely and efficiently, facilitating the smooth flow of materials from one place to another.

flange size chart in mm

Why Is Flange Sizing Important

Flange sizing is an incredibly important aspect of any industrial piping system design. It ensures that the flanges which connect the piping sections together can withstand the pressure and stress of fluid flow, without any leaks or damage. The size of the flanges depends on the outside diameter of the pipe, the wall thickness, and the pressure rating.

Choosing the right size flange for your application is critical because it affects the overall safety, performance, and lifespan of the entire piping system. Additionally, poor flange sizing or selection can lead to costly downtime, repairs, or even catastrophic leaks. To avoid these issues, it’s important to work with experienced engineers who can help you select the right flange size based on your specific application requirements.

Flange Size Chart

Looking for a flange size chart in mm? Look no further! A flange size chart is a handy tool for determining the size of flanges, which are used to connect pipes, valves, and other equipment. In the chart, you’ll find a list of flange sizes in millimeters, along with their corresponding dimensions and pressure ratings. These charts can be a bit overwhelming at first, but with a little practice, you’ll become an expert in no time.

It’s important to select the correct flange size for your specific application to ensure a secure and leak-free connection. Don’t settle for anything less than perfect. So, the next time you’re faced with the challenge of finding the perfect flange size, be sure to consult a flange size chart for guidance.

Understanding Flange Dimensions

When it comes to choosing the right flange for your project, understanding flange dimensions is crucial. A flange size chart can help simplify the process and ensure you select the appropriate flange for your application. A flange size chart typically includes information about the outside diameter, bolt circle diameter, number of holes, and bolt hole diameter for each flange size.

It’s essential to note that flanges come in different sizes, so it’s crucial to select the correct size to ensure optimal performance and safety. It’s also worth mentioning that flanges play a crucial role in connecting pipes, valves, and other equipment, which means getting the right size is essential for the smooth operation of your system. So, take the time to understand flange dimensions, and consult a flange size chart to make an informed decision.

Types of Flange Faces

Flanges are an essential component when it comes to connecting pipes, equipment, and valves. They come in various sizes, types, and materials. Flanges are attached to the end of pipes and then bolted together to form a long pipeline.

One important factor to consider when selecting a flange is the flange face. The flange face can come in different types, which include raised face, flat face, and ring-type joint. The raised face flange is the most commonly used type as it provides a greater surface area and helps reduce the risk of leaks.

The flat face flange, on the other hand, is commonly used in connection with a gasket to help seal the joint. Lastly, the ring-type joint flange is used in high-pressure systems that involve streams containing corrosive materials. When selecting flanges, it is crucial to refer to a flange size chart to know the exact dimensions required for the application in question.

It is also important to ensure that the flanges are made from materials that can withstand the pressure, temperature, and corrosive nature of the system they are installed in.

How to Measure Flange Size in mm

If you’re working with flanges, it’s essential to understand how to measure flange size in mm. Fortunately, there is a flange size chart that you can refer to for guidance. This chart contains all the necessary information you need to measure your flange size accurately.

To begin, you’ll need to identify the flange’s nominal size, which is typically indicated on the outside diameter. Next, determine the number of bolt holes and the bolt hole diameter. Then, measure the distance between the bolt holes, referred to as the pitch circle diameter.

This measurement helps to determine whether your flange is a metric or an imperial flange. Finally, take note of the flange faces, which can either be flat faces, raised faces, or ring-type joints. Knowing the flange size is crucial when selecting gaskets, valves, and pipes that fit your flange.

Remember to use a reliable and accurate measuring tool to ensure your measurements are correct. By following these steps, you’ll be confident that your flange will fit perfectly, and you’ll avoid costly mistakes during installation. The main keyword used organically: flange size chart

Flange Size Conversion

If you’re dealing with flanges regularly, it’s important to understand their size conversions to ensure that they fit perfectly. Flange sizes can be confusing as they are measured in both inches and millimeters. A flange size chart in mm can be a lifesaver, as it can help you determine exact measurements for specific pipe sizes.

For instance, a 2-inch flange may be equal to a 50mm flange. By using a flange size chart in mm, you can avoid costly mistakes and wasted time when trying to fit parts together. Whether you’re working on a residential or commercial plumbing project, it’s essential to get the measurements right, and accessing a flange size chart in mm can help you do just that.

Overall, understanding flange size conversions can streamline the process of installation and ensure that everything fits together perfectly.

Converting Inches to mm

Converting inches to mm can be a tricky task when it comes to flange size conversion. Flanges are a crucial component in mechanical and plumbing systems and their size is often specified in inches. However, in some cases, metric measurements are required, and that’s when the conversion comes into play.

To convert inches to mm, you can use a simple mathematical formula: multiply the measurement in inches by 2 This will give you the equivalent measurement in millimeters.

For example, if you have a flange size that is specified as 6 inches, you can convert it to mm by multiplying 6 by 24 which is equal to 154 mm.

It’s important to note that when it comes to flange sizes, there are standard measurements that might differ slightly from the converted mm measurements, so it’s always best to check the manufacturer’s specifications. Converting inches to mm is a quick and easy process and can help you ensure that your mechanical and plumbing systems are operating efficiently.

Converting DN to mm

If you’re dealing with pipelines or industrial systems, chances are you may have come across the DN (diameter nominal) unit of measurement. However, if you want to ensure that a particular flange fits in your system, you’ll need to convert its DN measurement into millimeters (mm). Thankfully, this conversion is quite straightforward.

All you need to do is multiply the DN value by 24, and you’ll have the flange’s diameter in mm. For instance, if you have a DN20 flange, you’ll multiply it by 2

4 to get 508mm. Alternatively, you could use online calculators and conversion charts to make this process even easier. Just remember that accurate flange size measurements are crucial for your industrial system’s safety and performance, so make sure you double-check your conversions.

By understanding how to convert DN to mm, you’ll be one step closer to ensuring that your industrial systems operate smoothly and efficiently.


So there you have it, folks! The flange size chart in mm may seem like a dry and insignificant topic, but it’s essential to ensuring that your piping systems fit together seamlessly. It’s amazing how a tiny measurement can have a big impact on the overall functionality of a system. Remember, when it comes to flanges, size really does matter!”


What is a flange size chart in mm used for?
A flange size chart in mm is a reference tool that provides the measurement specifications for the different types and sizes of flanges used in piping and engineering projects.

Can I use a flange size chart in inches instead of mm?
It is not recommended to use a flange size chart in inches if the project requires measurements in mm. Converting measurements may lead to inaccuracies and errors in the installation process.

How do I read a flange size chart in mm?
A flange size chart in mm typically lists the dimensions of the flange, including the outside diameter (OD), bolt circle diameter (BCD), and number of bolt holes. The chart may also provide information on the thickness of the flange and the diameter of the holes.

Are flange size charts in mm standardized?
Yes, flange size charts in mm are typically standardized based on international or industry standards, such as the ASME B16.5 or DIN EN 1092-1. However, it is important to double-check the specific requirements for each project to ensure compliance.

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