90 Durometer O-Ring - Nitrile Buna-N General Purpose

Buna-N (NBR) 70 durometer is a softer, more flexible compound that provides excellent sealing under low to medium pressures and conforms easily to mating surfaces. The 90 durometer version is significantly harder and stiffer, making it better suited for high-pressure hydraulic applications, tight tolerances, and environments where extrusion resistance is critical. The 70 durometer offers more elasticity; the 90 durometer offers greater structural rigidity.

90 durometer Nitrile Buna-N O-Rings are used in high-pressure hydraulic systems, pneumatic systems, oil and gas equipment, heavy machinery, and automotive applications. Their increased hardness provides superior resistance to extrusion and abrasion, making them ideal for dynamic sealing environments where softer compounds would deform under load.

Detroit Sealing Components stocks 90 durometer Nitrile O-Rings in AS568, JIS B2401, metric, and other international standards including BS 4518, GB/T 3452.1, SMS 1586, and JASO F404. Custom and unlimited inner diameter sizes are also available through continuous molding processes, covering cross-sections from 3mm to 25mm.

Yes. Nitrile Buna-N (NBR) is one of the most widely used elastomers for oil and fuel resistance. At 90 durometer, the compound retains NBR's inherent resistance to petroleum-based oils, hydraulic fluids, and fuels, while offering enhanced hardness that reduces deformation in high-pressure or high-extrusion-risk environments.

Yes. Detroit Sealing Components offers custom and unlimited-size O-rings manufactured via continuous molding, eliminating the need for costly tooling. Any inner diameter is achievable with standard cross-sections ranging from 3mm to 25mm, making it possible to meet unique application requirements without long lead times or high tooling costs.

Choosing the right durometer depends on system pressure, groove dimensions, dynamic versus static application, and extrusion gap. For high-pressure hydraulic or pneumatic systems with tight clearances, 90 durometer is typically preferred. For low-to-medium-pressure static seals requiring flexibility, 70 durometer is more common. Detroit Sealing's technical team can provide application-specific guidance to help you select correctly.