Square & Quad Rings

O-Ring Square Rings (Square Profile Rings)

APG’s Square Rings feature a square cross-section that delivers stable sealing for both static and dynamic applications. Available in-stock in common sizes and materials such as Buna-N (NBR), Viton (FKM), EPDM, and silicone, square-profile rings are often specified for hydraulic and pneumatic components where groove designs benefit from increased contact area. APG also offers custom kitting to standardize what you stock and simplify maintenance and replenishment.

Quad Rings (X-Rings)

APG’s Quad Rings, also known as X-Rings, use a four-lobed profile engineered for reliable sealing in both static and dynamic applications. Stocked in common sizes and materials including Buna-N (NBR), Viton (FKM), EPDM, and silicone, Quad Rings are frequently used in pumps and valves where they can provide more stable sealing than standard O-rings in certain conditions. For easier inventory control, APG can build custom kits tailored to your most-used sizes and materials.