Oil Seal Types

We can't emphasise enough how important it is to choose the right oil seal to keep your application functioning, and functioning well. Not every oil seal is the same. Manufactured using various material elastomers and to suit a range of dimensions, seals are as unique...

Rotary Shaft Seals

Rotary shaft seals are the more formal name for this type of seal; however, we also know them as oil, grease, fluid, or dirt seals. Whatever you call them however, they all perform the same function – to close the space between stationary and moving parts in machinery...

Silicone O Rings

As a leading O ring UK manufacturer and supplier of high quality seals and gaskets, offering a wide range of types, sizes, and sealing solutions that suit various applications across all industries, we work hard to ensure you get the best sealing solution for your...

Viton O Rings

Viton o rings bring with them numerous advantages, especially for applications within high-tech and critical industries. Providing great resistance to wide fluctuations in temperature and chemical ranges as well as being wholly suitable for pressure applications,...

Pipe Gasket

A pipe gasket is designed to seal a space between two sections of a pipe. Many pipes have flanged surfaces where they join, which means it isn’t smooth or flat to make this connection secure. In order to overcome this flared area, a flange gasket will be used to...

Spiral Wound Graphite Fill Gasket

With so many different gasket options on offer today, we know it can be difficult deciding which ones have the right features for your needs. Each type of gasket is suitable for a variety of applications or uses, and the material that your gasket is made from will...

Gasket Cutting

Using the latest technology and equipment, gasket cutting today offers incredible precision. Achieving customised gaskets that meet your sealing requirements, today we’re now seeing various gasket cutting techniques used as we move away from the standard dimensions...

What are Bonded Seals?

As you start to compare the seals on offer on our site, you’ll find that there are many different options for a variety of uses. Bonded seals are a great solution for some applications, offering many benefits over other types of seals. Specialist Sealing Products...

Rubber Gasket Material

Rubber gaskets are a very valuable solution for a variety of uses, however, you’ll want to make sure you always choose the right option for your unique business operations. There are a variety of rubber gasket materials on offer, which provide you with an effective...

Installation of Spiral Wound Gaskets

Spiral wound gaskets are crucial in the prevention of leaks. Used across various industries, we know that spiral wound gaskets can provide the perfect sealing solution.  We also understand that your ultimate goal when working with gaskets is to ensure they fit...

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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