Metric O-Rings

Allied Metrics Seals & Fasteners, Inc. is a reliable and reputable manufacturer of high-quality metric o rings for various industries. These industries typically operate hydraulic systems where o-rings are required to prevent leaks. However, it’s also ideal for different applications, so we offer them in different sizes and materials for various applications.

Our o-rings are highly durable and offer superior sealing performance to protect your equipment from any damage. Our quality assurance process guarantees that each of our o-rings meets industry standards for quality and safety. 

We provide superior customer service, so you can be sure your needs will always be addressed. In addition, we can work with you to ensure your project’s success.

Metric O-Ring Kit from Allied Metrics Seals & Fasteners, Inc.

At Allied Metric Seals & Fasteners, Inc., we offer metric o-ring kits used for routine maintenance. These kits come with o-rings in different metric sizes, which apply to facilities with various components. Each kit comes with several pieces of o-rings for various equipment or machines.

Our o-ring kits also come with a comprehensive selection guide, which helps you find the right o-ring size and material for your needs. If you have missing seals or an unknown dimension for some parts, you can always choose a metric o-ring kit. These will save you from repairs as quick solutions suit the job.

Customized O-Rings from a Reliable ManufacturerFood Grade O-Rings and seals-Materials Selection Guide

We’re one of the leading manufacturers of hydraulic seals that have been in the industry for many years. Due to our devotion and commitment to our clients, we ensure to have an in-depth knowledge of what each industry needs. It requires us to be familiar with the equipment used in your facility. 

If you need help finding the right size or type of o-ring, we can give some solid advice to deliver exceptional results. We understand that not all of our clients have the exact requirements. It’s why we also offer custom-made o-rings. We can give your specifications, from the material to size and shape, so that you have an o-ring that’s perfect for the application or job you’re using it for.

Choose Allied Metrics Seals & Fasteners for Your Metric O-Ring Needs

We’re your trusted manufacturer in metric o-rings and specialize in using different materials to ensure the outcome is what you expect. Whether the project is big or small, rest assured that we can handle it with no second thoughts.

If you have any questions or concerns about our products, don’t hesitate to contact us today. You may also request a quote; we’re ready to send estimates for your projects. At the same time, we’ll find the best solution so you won’t have to worry anymore.

What is a Metric O-Ring?

Generally, o-rings are circular gaskets or seals that prevent equipment or system from leaking fluids or gasses, which may affect the machinery. They’re made from rubber or plastic and do an excellent job of sealing since they come in different configurations.

A metric o-ring is not different from a standard o-ring since its sizes are only defined in millimeters. For instance, standard o-rings are developed for the United States use. On the other hand, the international community uses metric o-rings.

It’s broken down by region, so metric o-rings are used in Europe and Asia. Their thickness is measured using the metric system, making them the ideal option for equipment in countries that use the metric system. It’s why we offer o-rings in standard and metric options.

Common Applications of Metric O-Rings

Metric o-rings are no different regarding applications and use with other o-rings. They have the same benefits and features, except if made with different materials. 

To give you an idea. Below are some of its typical applications:

  • Pneumatic systems
  • Hydraulic valves
  • Pumps
  • Oil systems
  • Pump shafts
  • Hydraulic cylinders

In addition, o-rings are used by different industries for various applications. These industries are as follows:

  • Aerospace: The aerospace industry uses metric o-rings in its aircraft fuel systems.
  • Automotive: Automobile fuel systems also utilize metric o-rings for sealing.
  • Gas and Oil Refineries: These industries have oil systems requiring metric o-rings.
  • Water Treatment: Water treatment facilities need o-rings for their pipes and valves.
  • Chemical Processing: Chemical plants require metric o-rings to prevent dangerous liquids or gasses from leaking.

With these in mind, looking for the right o-ring size for your equipment is necessary. Find out if these are made in countries where they use millimeters or metric sizes. Our team will gladly guide you if you need help determining the right size.

Materials Recommended for Metric O-Rings

It’s worth noting that metric o-rings come in different sizes and materials. Each material used in manufacturing these are recommended for particular applications.

Here are the common recommended materials:

Viton

Also known as Fluorocarbon, this material is suitable for outdoor use since they’re valued for its resistance to different chemicals, high temperatures, and elements. It’s applicable for diverse sealing applications that involve movement. It can also handle some acids, such as halogenated hydrocarbons.

Silicone

Best used in applications with a temperature range of -120 and 450 degrees Fahrenheit. These are commonly found in the medical industry or hot air applications. It has poor abrasion resistance, so it’s suited for static applications. However, o-rings made of silicone perform well when exposed to steam, steam, or petroleum fluids.

PTFE

These are ideal for applications with a temperature range of -100 and 500 degrees Fahrenheit. These o-rings have non-stick characteristics with a shallow friction surface ideal for high temperatures. Pure PTFE o-rings are rigid and stiff. But encapsulated PTFE has significant surface wear and showcases abrasion and wear resistance.

EPDM

Short for Ethylene Propylene, EPDM o-rings possess outstanding resistance to weathering, sunlight, and ozone. It’s fantastic for temperatures between -65 to 300 degrees Fahrenheit, and it’s used in industries where fluid handling and hygiene are necessary. O-rings made from EPDM are also resilient to different chemicals and steam, making them the ideal choice for outdoor applications.

Buna-N

Nitrile o-rings are perfect for petroleum-based applications and lubricants, and it’s a cheaper alternative than other o-ring elastomers. It’s primarily used in applications where limited temperature is employed with resistance requirements.

Each material has its benefits and features. Looking for the right choice for various projects or purposes can be challenging. Therefore, you should determine your equipment’s characteristics to decide which materials suit it.

Viton O-Rings

The Two Main Forms of Metric O-Rings

Whatever material metric o-rings are made of, they come in static and dynamic forms. Understanding the differences between the two will allow you to select the correct type for your equipment.

Static Applications

Static refers to a seal that’s not in motion, which means it remains stationary and not moving. Moreover, static applications include fluid or gas sealing applications where the o-ring is compressed, a vulcanized solid, and the material is resistant to fluid or gas. It’s also ideal for maintaining a vacuum or containing pressure.

Dynamic Applications

Dynamic refers to the seal and the equipment having relative motion. It means the o-ring is more likely to be exposed to more significant wear and tear as it must continuously slide along its static counterpart. It’s why dynamic applications, such as rotating pumps, shafts, and cylinder pistons, require durable materials with high tensile strength.

Static & Dynamic O-Ring Sizes & Groove Dimensions

Static & Dynamic O-Ring Sizes & Groove Dimensions

Static & Dynamic O-Ring Sizes & Groove Dimensions

In the o-ring size diagram above, the measurement “b” (which is the width of the groove) must be larger than the deformed o-ring itself. Depending on application, the groove may be open on one side. However, the pressure applied to the medium to be sealed must have full access to the o-ring. The surfaces of the groove and the opposing surfaces should have (more or less) rounded processing traces to permit peak-to-valley heights of 44 to 25 μm.

Static Seal Groove Dimensions

d2 t b
1 0,8 1,3
1,5 1,1 1,9
1,6 1,2 2,1
1,78 1,3 2,3
1,9 1,4 2,4
2 1,5 2,6
2,4 1,8 3,1
2,5 1,9 3,2
2,62 2,0 3,4
2,7 2,1 3,5
3 2,3 3,9
d2 t b
3,5 2,7 4,5
3,53 2,7 4,5
3,6 2,8 4,7
4 3,15 5,2
4,5 3,6 5,8
5 4 6,5
5,33 4,3 6,9
5,5 4,5 7,1
5,7 4,65 7,4
6 4,95 7,8
6,5 5,4 8,4
d2 t b
6,99 5,85 9,1
7 5,85 9,1
7,5 6,3 9,7
8 6,75 10,4
8,4 7,15 10,9
8,5 7,25 11,0
9 7,7 11,7
9,5 8,2 12,3
10 8,65 13

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View diagrams and tables as a
PDF: Static Groove Dimensions

In case of applying back-up rings, the width of groove “b” is increased by the width of the back-up ring resp. in case of support on either side by the double width of the back-up ring.

Dynamic Seal Groove Dimensions by Application

Dynamic Seal Groove Dimensions by Application

Dynamic Seal Groove Dimensions by Application

Application: Hydraulics

d2 t b z
1 0,9 1,3 1
1,5 1,3 1,9 1
1,6 1,4 2 1,1
1,78 1,5 2,3 1,1
1,9 1,6 2,4 1,2
2 1,7 2,4 1,2
2,4 2,1 2,9 1,4
2,5 2,2 3 1,4
2,62 2,3 3,1 1,5
2,7 2,4 3,2 1,5
3 2,6 3,6 1,6
d2 t b z
3,5 3,1 4,2 1,8
3,53 3,1 4,2 1,8
3,6 3,2 4,3 1,8
4 3,5 4,8 2
4,5 4 5,4 2,3
5 4,45 6 2,5
5,33 4,7 6,4 2,7
5,5 4,95 6,6 2,8
5,7 5,1 6,9 3
6 5,4 7,2 3,1
6,5 5,8 7,8 3,3
d2 t b z
6,99 6,3 8,4 3,6
7 6,3 8,4 3,6
7,5 6,7 9 3,8
8 7,2 9,6 4
8,4 7,6 10,1 4,2
8,5 7,7 10,2 4,2
9 8,2 10,8 4,3
9,5 8,6 11,4 4,4
10 9,1 12 4,5

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Application: Pneumatics

d2 t b z
1 0,95 1,3 1
1,5 1,35 1,9 1
1,6 1,45 2 1,1
1,78 1,55 2,3 1,1
1,9 1,75 2,4 1,2
2 1,8 2,4 1,2
2,4 2,15 2,9 1,4
2,5 2,25 3 1,4
2,62 2,35 3,1 1,5
2,7 2,45 3,3 1,5
3 2,75 3,6 1,6
d2 t b z
3,5 3,25 4,2 1,8
3,53 3,25 4,2 1,8
3,6 3,35 4,3 1,8
4 3,7 4,8 2
4,5 4,2 5,4 2,3
5 4,65 6 2,5
5,33 4,95 6,4 2,7
5,5 5,15 6,6 2,8
5,7 5,35 6,9 3
6 5,65 7,2 3,1
6,5 6,1 7,8 3,3
d2 t b z
6,99 6,6 8,4 3,6
7 6,6 8,4 3,6
7,5 7,1 9 3,8
8 7,6 9,6 4
8,4 7,9 10,1 4,2
8,5 8 10,2 4,2
9 8,5 10,8 4,3
9,5 9 11,4 4,4
10 9,5 12 4,5

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View diagrams and tables as a
PDF: Dynamic Groove Dimensions