O Ring Slot Chart

Can O-rings be used in rectangular or non-circular groove patterns? This question comes up weekly, and the answer is a resounding “Yes!” however there are definite guidelines we want to follow. A non-circular face seal footprint might also be called a racetrack groove, a wandering groove or a custom plan view. When using an O-ring, the main design consideration is the corner or smallest radius (shown “r” in diagram). The inside radius should be at least three times the O-ring cross sectional diameter. In a perfect world, six times greater is even better. What we want to avoid is over-stressing the O-ring around the bend, or causing a corner crease which increases likelihood of corner leakage. Designing the radius at six times the cross section will minimize the bending stress, resulting in increased service life.

1. O'ring Groove Chart
2. O Ring Slot Size Chart

ISO 3601 Metric O-Rings Size Chart Issued by the International Organization for Standardization, the ISO 3601 standard contains two groups of O-Rings, Class A and Class B. Class A corresponds to the American standard AS 568B in its current format (the 900 series tube fitting O-Rings are not included). General Engineering Menu O-Rings Suppliers Molded O-Rings Services. The following chart gives typical gland dimensions for common o-ring sizes. Please consult with your o-ring manufacturer for custom or application specific requirements. To use this document, first identify if you have a female or male o-ring gland requirement. And thus prolong the service life of O-rings. The Parbak® numbers correspond to the size designa-tions of the 2-xxx series of the Parker O-rings they are installed with (e.g. 8-211, N 300-90 fits O-ring 2-211, N 674-70). ParCoat® Coating O-rings with ParCoat ® coatings can be assembled with low exertion of force using automatic equipment.

Ideal design: r > 6 x W diameter but no less than r > 3 x W diameter

To minimize installation difficulties arising from stretch or OD compression on the seal, the centerline perimeter of the groove should match the centerline circumference of the O-ring. The rectangular cross section of the groove will follow the suggested guidelines in the O-Ring Handbook.

For those times when hardware real estate is at a premium and we simply cannot increase the inside corner radii to the desired size, an alternative option is the O-Seal. The O-Seal has a round cross section like an O-ring. However the footprint of the O-Seal is designed to match the shape of the groove. The primary advantage of the O-Seal is custom molding to fit the exact groove, eliminating the concern that comes with bending stress at the corners. A smaller corner radii can be used for the groove, allowing the footprint to fit perfectly within the application’s design constraints.

If there are multiple ports or openings on the face, or bolt holes to contour around, these seals can be consolidated into a single O-seal solution. By consolidating seals, the installation process becomes much easier. All seals are ready to be installed at the same time, and the risk of installing the incorrect seal material is eliminated. This may offer the added advantage of streamlining the bill of materials and simplifying the amount of stock to be replenished during the assembly process.

O-Seals are available in nearly every material family and engineered for optimum size and configuration for each unique application. Parker Application Engineers are happy to assist you with your racetrack groove design or a custom O-Seal. Please contact us today via online chat or by email by visiting Parker O-Ring and Engineered Seals Division website.

This article was contributed by Dorothy Kern , applications engineer lead, O-Ring & Engineered Seals Division

Related content:

U.S. and Metric O-Ring Sizes, Quad-Ring Seals, Rubber X-Ring Seals, Rubber Square-Ring Seals

The proper o-ring size is a fundamental aspect of proper o-ring performance. Whether your application conforms to U.S., Japanese JIS, British BS, or Common Metric sizing for o-rings, these o-ring size charts will help you locate the right o-ring size. If the o-ring, quad-ring, x-ring or square-ring you need doesn't fit these standards, custom and non-standard products are available for most materials with no tooling or setup fees.

You can contact us or request a quote online to quickly and easily order o-rings, x-rings, square-rings or other non-standard products.

O'ring Groove Chart

STANDARD O-RING SIZES CHARTS

O Ring Slot Size Chart

STANDARD X-RING SIZES CHARTS

STANDARD SQUARE RING SIZES CHARTS