O-Ring Offerings

o-rings of all sizes

We distribute O-rings manufactured according to metric and imperial international standards, such as AS 568B, DIN ISO 3601, and JIS. Whether miniature O-rings, special O-rings with large dimensions, or continuously moulded and spliced cord, a wide selection of custom sizes for almost any dimension are possible . At Great Lakes Rubber, we sell O-rings which utilize compounds formulated to meet the most stringent industry standards including: FDA, USP, KTW, DVGW, BAM, WRAS (WRC), NSF, Underwriters Laboratories (UL), Aerospace (AMS), and many other customer-specific requirements.

Great Lakes Rubber stocks, packages, and distributes our O-rings based on customer need and inventory flow.

Basic O-Ring Elastomers

elastomer o-ring
  • Acrylonitrile-Butadiene (NBR)
  • Carboxylated Nitrile (XNBR)
  • Ethylene Acrylate (AEM, Vamac)
  • Ethylene Propylene Rubber (EPM, EPDM)
  • Butyl Rubber (IIR)
  • Chloroprene Rubber (CR)
  • Fluorocarbon (FKM)
  • Fluorosilicone (FVMQ)
  • Hydrogenated Nitrile (HNBR, HSN)
  • Perfluoroelastomer (FFKM)
  • Polyacrylate (AC)
  • Polyurethane (AU, EU)
  • Silicone Rubber (Q, MQ, VMQ, PVMQ)
  • Tetrofluoroethylene-Propylene (AFLAS™)

What is an O-Ring?

An O-ring is a torus, or doughnut-shaped ring, generally molded from an elastomer, although O-rings are also made from PTFE and other thermoplastic materials, as well as metals, both hollow and solid. This handbook, however, deals entirely with elastomeric O-ring. (note: see the Parker O-Ring Handbook, which is provided, below, in a PDF for your convenience.)

Great Lakes Rubber

O-rings are used primarily for sealing. The various types of O-ring seals are described in the section called Scope of O-ring Use. O-rings are also used as light-duty, mechanical drive belts. More information, including design criteria on O-ring drive belts and their application can be found in the O-Ring Applications section.

So what is an O-Ring Seal?

An O-ring seal is used to prevent the loss of a fluid or gas. The seal assembly consists of an elastomeric O-ring and a gland. An O-ring is a circular cross-section ring molded from rubber. The gland - usually cut into metal or another rigid material - contains and supports the O-ring. The combination of these two elements; O-ring and gland - constitute the classic O-ring seal assembly.

How an O-Ring Works


O-ring seated on piston

All robust seals are characterized by the absence of any pathway by which fluid or gas might escape. Detail differences exist in the manner by which zero clearance is obtained - welding, brazing, soldering, ground fits or lapped finishes - or the yielding of a softer material wholly or partially confined between two harder and stiffer members of the assembly. The O-ring seal falls in the latter class.


1. Piston and O-ring installed in bore

The rubber seal should be considered as essentially an incompressible, viscous fluid having a very high surface tension. Whether by mechanical pressure from the surrounding structure or by pressure transmitted through hydraulic fluid, this extremely viscous fluid is forced to flow within the gland to produce "zero clearance" or block to the flow of the less viscous fluid being sealed. The rubber absorbs the stack-up of tolerances of the unit and its internal memory maintains the sealed condition.


2. O-ring sealing fluid toward the pressure source

Figure 1 - illustrates the O-ring as installed, before the application of pressure. Note that the O-ring is mechanically squeezed out of round between the outer and inner members to close the fluid passage. The seal material under mechanical pressure extrudes into the micro fine grooves of the gland.

Figure 2 - illustrates the application of fluid pressure on the O-ring. Note that the O-ring has been forced to flow up to, but not into, the narrow gap between the mating surfaces and in so doing, has gained greater area and force of sealing contact.

O-Ring Advantage

Great Lakes Rubber
  • O-rings seal over a wide range of pressure, temperature, and tolerance.
  • Ease of service, no smearing or retightening.
  • No critical torque on tightening, therefore unlikely to cause structural damage.
  • An O-ring normally requires very little space and are light in weight.
  • In many cases, an O-ring can be reused which is an advantage over non-elastic flat seals and crush-type gaskets.
  • The duration of life in the correct application corresponds to the normal aging period of the O-ring material.
  • O-ring failure is normally gradual and easily identified.
  • Where differing amounts of compression effect the seal function (as with flat gaskets), because metal to metal contact is generally taken into account, an O-ring is not effected.
  • They are cost-effective.

Which One Should I Choose?

Great Lakes Rubber

With so many options available, it can seem daunting. Fortunately, Parker provides a quick and easy-to-use online O-ring selection tool to assist with this decision. Check it out: Parker O-Ring Selector.

Parker also offers a brand new and innovative online "Product Showcase" tool which is simple yet beneficial in facilitating your choice of seal and o-ring products specific to your particular needs. It enables you to easily do so in conjunction with our knowledgable sales professionals.

For your convenience, Great Lakes Rubber is proud to present the Parker .

Milwaukee: (414)352-8800 or
Rockford/Loves Park: (815)654-8188

Strategic Statement

Great Lakes Rubber strives to meet our customer's global requirements through excellent customer service, alignment with world class suppliers, and continuous improvement of our quality management system.

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