The H90403 is an AS568-403 black Buna-N (Nitrile) 90 Shore A O-Ring with an inside diameter of 1.725 in (43.82 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 2.275 in (57.79 mm). This o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.
The material holds up against greases and lubricants, hydraulic fluids, and water. That behavior comes from the compound itself: Buna-N (Nitrile) is known for the most widely specified general-purpose sealing elastomer, reliable performance in both static and dynamic service. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. It should not be specified for service in strong acids or automotive brake fluid.
Maintenance and OEM teams specify it across hydraulic and pneumatic systems, automotive, and construction equipment.
Stocked as H90403 and sold individually. Unit weight is approximately 8.6188 g. As always, verify media compatibility and operating conditions against the requirements of your specific application.
Description -403 BLACK BUNA 90D O-RING
Actual Cross Section 0.275 inch (6.99 mm)
Actual Inside Diameter 1.725 inch (43.82 mm)
Actual Outside Diameter 2.275 inch (57.79 mm)
Measurement System Imperial
Product Category O-Rings - Bulk - Commodity