Threaded Flange

Threaded flanges are probably the most recognisable of all flanges due to their screw thread design that is used to connect it to the pipe. Threaded flanges, also known as screwed flanges (for obvious reasons), require a male and female thread to create a connection...

Slip On Flange

A slip-on flange can also be known as a hubbed flange, which, as the name suggests, has a hub with a very low profile. Why is this important? Because this type of ring type joint gasket has an internal diameter larger than the connecting pipe, allowing you to slide it...

Weld Neck Flange

Also known as tapered hub flanges or high hub flanges, weld neck flanges are a specific type of gasket with a protruding ridge and long neck used to connect pipework and provide you with a high-quality seal. Weld neck flanges, in particular, are a popular choice when...

Nitrile vs Viton® – What is the Difference?

As you start to make a decision about what type of O-rings to purchase for your business, you might wonder what material is the most suitable for your unique needs. Every business operation has different requirements for their O-rings, such as the temperature,...

Aflas vs Viton

When it comes to choosing O ring suppliers in the UK, you’ll find that there are a wide range of materials on offer for you to choose from. Many people find that the options can seem quite overwhelming, with some materials having similar properties but offering...

EPDM Gasket

Both the automotive and construction industries have started to use EPDM gaskets more frequently in recent times. This rubber material is UV light resistant and has many fantastic properties that make this part highly effective for a wide range of processes. Keep...

Metal Gaskets

When comparing gaskets for use within your business processes, you’ll find that these can be made from a variety of materials. Metal gaskets are a very popular option, offering many advantages over other materials. When looking at sealing product options, make sure...

AFLAS o ring

O rings come in many different dimensions, thicknesses, and materials. And it is the various different materials that o rings can be manufactured from that make each o ring unique and suitable for specific applications. In fact, there are hundreds of different types...

O Ring Vulcanization Process

With years of o ring knowledge and experience in o ring vulcanization, we're one of the leading experts in providing the right sealing solution for you. To view our full range, visit our O-ring product page, with a wide selection and something to match every...

What is a Window Seal?

A window seal is something that nearly all of us will have seen in our homes or workplaces and is designed to help make your building more comfortable. Within our range of Sealing Specialist Products, we offer a selection of window seals designed for various...

See our latest catalogue for all the services we offer.

How are O Rings made?

O rings are one of the most common components within manufacturing. Suitable for a range of applications and found in numerous everyday appliances, o rings are a vital piece of equipment to provide the perfect sealing solution.

Ring-shaped seals, o rings are made up of various compounds and elastomers and are designed to prevent leaks from occurring between two mating surfaces.

As O-rings can be made up of various materials to suit the application in which they will be used, O-ring manufacturers must work with their clients to fully understand where the O-ring will be placed and what elements it will be exposed to (high temperatures, abrasive chemicals, etc), to ensure the right O-ring is supplied.

In this post, we look at the o ring manufacturing process, what it entails, why it’s important, and the information you need to know to make the most informed decision for your application.

How O Rings Are Made and its Use

O-ring Process

The O-ring manufacturing process starts with using the right tools and equipment. O-ring suppliers must be able to manufacture various O-rings from varying materials and put these through the correct processes using the right tools and equipment.

This is to ensure that O-rings are moulded to the correct shape and size (O-rings can come in various depths and sizes depending on specifications), with the two halves of an O-ring manufactured and then moulded together to form the ring.

Once the right tools and equipment have been identified, we move on to the milling process.

Milling is a very precise part of the manufacturing process and involves choosing the most suitable materials for the O-ring to ensure you achieve the perfect seal.

The milling process will involve mixing fillers, additives, and other ingredients using a milling machine.

(Make sure to check out our post on the benefits of choosing Viton O-rings for your applications).

Once the elastomer material is complete, the sheet metal is then cut into strips and placed into an extruder. This part of the O-ring process is designed to reduce the metal’s overall viscosity by heating the metal and forcing it through a die.

For example, the raw material is forced through one or a series of dies that will take on the o-ring shape. There are various extrusion forms, and the o ring manufacturer will work with the one most suited to the material.

Forms of extrusion can include:

  • Heat
  • Cold
  • Friction
  • Micro.

The size of the final cords produced will, of course, be dependent on the O-rings requirements and specifications.

From the production of the cords, we then move to heated moulds, where the cords are cut into shape and size and moulded together in the press, forming them into the O-ring shape (this is also known as compression moulding, which involves using heat and pressure to create the o ring. In some instances, rubber is pre-heated and then injected into the cavity of the mould; the mould is then sealed tight, placing pressure on the mould; as the pressure increases, the rubber (or any pre-heated material) will begin to take the shape of the mould).

Transfer moulding is similar to that compression moulding; however, rather than injecting material into an open mould cavity, transfer moulding works by using a closed mould cavity, allowing you to create a higher level of pressure on the mould, so the finished product, i.e., the o ring is thicker and more consistent.

The final type of moulding is injection moulding. In this instance, the raw material is injected directly into the mould cavity. Here, the raw material often takes the form of pellets, which are then heated to a liquid state and injected into the mould.

You will need to work closely with your chosen ring supplier to select the best and most appropriate solution for you.

Within the mould, O-rings are left to cure until they are ready to be carefully removed.

There will undoubtedly be excess material surrounding the o ring which will need to be

removed. This is carried out during the finishing process to produce a perfectly round, smooth, O-ring. (Note: For larger O-rings, the process of buffing will be used to remove the excess in a smoother action).

All o rings will go through a curing process, where once the o rings have been carefully removed from their moulds, they are then placed in large industrial ovens for between 2 and 18 hours (depending on the elastomer within the o ring).

The final step of the o ring process is quality control.

Carrying out thorough quality checks and inspections at every stage, checking for any visual defects, and checking dimensions and measurements are as specified is vital to reduce waste, time, and resources.

O ring suppliers will finally receive the specified o rings packaged and ready for use.

O ring Supplier UK

At Specialist Sealing Products, we supply a wide selection of o rings to suit various applications across diverse industry sectors.

With a wide range of stock and efficient delivery times, contact us today at 01535 274 776 or email your requirements to to see how we can help.



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