O-Rings

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An O-ring is the cheapest part in most assemblies and the most common cause of a warranty return. We mould O-rings in twelve compounds, hold the complete AS568 mould set so standard sizes need no tooling, and cut new tools in our own workshop when a drawing falls outside the standard. That combination is what lets us give the same answer to a standard dash number and to a one off cross section.

Product Photographs

Every image on this page is a photograph of parts we have produced.

Key Benefits

• Standard AS568 sizes produced from existing moulds with no tooling charge or tooling lead time
• Non standard cross sections tooled properly instead of substituted with the nearest stock size
• Twelve compounds from one supplier so a mixed seal schedule stays on one purchase order
• Compound selected by our own formula engineers against your medium and temperature
• Repeat orders run from the same tool and the same formulation

Problems It Solves

• A non standard size that stock suppliers will not tool and keep offering to substitute
• Seals that swell or harden because the compound was chosen from what the factory already ran
• Cross sections that drift between batches when the moulder changes without notice
• Five different seal vendors for one machine's seal schedule

Who It Is For

• Design engineers releasing a groove design who need the seal to match the drawing
• Maintenance and MRO buyers replacing seals on equipment whose original supplier is gone
• Purchasing teams consolidating O-rings in several compounds onto one supplier
• Distributors carrying an industrial seal programme

Application Scenarios

• Hydraulic systems where the ring prevents fluid leakage between connected parts
• Pneumatic systems sealing air and preventing pressure loss
• Automotive engines and industrial machinery in static and dynamic duty
• Water filtration systems where no contaminant may bypass the filter
• Machine tools, instrumentation and construction machinery

What You Are Actually Buying

Only values our own records support appear here. Anything we cannot evidence is left out rather than estimated.

Product Type	Moulded elastomer O-ring
Compounds Available	FKM, FFKM, SIR, EPDM, NBR, SBR, FVMQ, AEM/ACM, HNBR, CR, NR, CSM
Standard Size Range	Complete AS568 series, moulds held in house
Non Standard Sizes	Tooled to customer drawing in our own mould workshop
Duty	Static and dynamic sealing
Country of Manufacture	China

Materials

• FKM
• FFKM
• SIR silicone
• EPDM
• NBR
• SBR
• FVMQ
• AEM/ACM
• HNBR
• CR
• NR
• CSM

Manufacturing Process

• Compound selection
• Mould design
• Mould manufacture
• Rubber moulding
• First article approval
• Inspection and packing

Technical Features

• Moulded from a compound chosen against the medium rather than from stock
• Standard imperial sizes drawn from the complete AS568 mould set
• Custom cross sections designed and tooled by our own mould workshop
• Simple design that installs quickly with no special tooling at assembly

Quality Control

• Drawing or sample reviewed by our structural design team before quotation
• First article moulded from the production tool and approved by the customer
• Production checked against the approved first article before packing
• Process owned by our own rubber process engineers rather than subcontracted blind

Customisation Options

• Any AS568 dash number in any of our twelve compounds
• Custom inside diameter and cross section to drawing
• Colour coding by compound where a plant needs visual identification
• Mixed compound and mixed size schedules on one order

Where This Is the Right Choice and Where It Is Not

Compared With Nearest stock size substitution

A substituted size fits the groove diameter and still leaks because the cross section is wrong. We tool the size instead.

Compared With A single compound supplier

A machine with an oil circuit and a water circuit needs two compounds. One supplier holding twelve keeps that on one order.

Compared With Moulded gaskets

An O-ring in a designed groove is cheaper and more repeatable than a flat gasket for round sealing faces.

How to Specify and Order This Part

• Quote the AS568 dash number where one exists rather than a measured inside diameter

Quote the AS568 dash number where one exists rather than a measured inside diameter

• Give the medium, the continuous and peak temperature and the pressure with the size

Give the medium, the continuous and peak temperature and the pressure with the size

• State whether the seal is static or moving, because it changes both compound and profile

State whether the seal is static or moving, because it changes both compound and profile

• Check the groove clearance at maximum pressure to avoid extrusion

Check the groove clearance at maximum pressure to avoid extrusion

• Keep seals out of direct sunlight and heat in storage

Keep seals out of direct sunlight and heat in storage

Related Products

AS568 O-Ring Series

We possess all the moulds for the AS568 O-ring size range, which lets us supply standard parts of the series promptly and without a tooling step.

NBR O-Rings

NBR is the working compound for anything that meets oil or fuel at moderate temperature.

EPDM Seals and EPDM O-Rings

EPDM has good weather resistance and unusual versatility, which is why it appears across automotive, electrical and electronic products, daily necessities, sports equipment and mechanised industrial equipment, as well as in wires, cables and high voltage and ultra high voltage insulation materials.

Y Seals and Y O-Rings

A plain O-ring is not the right answer for every dynamic duty, which is why the Y profile exists.

Related Guides and Industries

How to Choose a Rubber Seal Material in Six Questions

Six questions decide almost every seal material choice. Answer them before you ask for a price, and the quotation you get back will be worth comparing.

The AS568 O-Ring Size Standard and Why It Saves You Tooling

AS568 is the reason some O-ring quotations come back with no tooling charge and a short lead time, and others do not.

O-Rings Questions

It depends on size and compound. For standard AS568 sizes it is low because no tooling is involved. Send the size list and quantity and we will tell you before you commit.

Standard AS568 sizes skip the tooling step entirely, which is the main lead time saving. We will quote a firm lead time with the price rather than publish a general figure.

Send a photo with the inside diameter and cross section measured, plus the application. We can identify the size, though an unknown compound cannot be identified by eye.

No. We hold the complete AS568 mould set.

Yes, and it is the usual reason buyers consolidate here.

Packing is agreed with you before production. Tell us your warehouse and labelling requirements with the inquiry.

Terms are agreed per order and confirmed in the proforma invoice. Ask with your inquiry.

Quote O-Rings

Send the size or drawing, the working conditions and the quantity. One working day for a considered reply.