-278 BLACK BUNA 90D O-RING

The H90278 is an AS568-278 black Buna-N (Nitrile) 90 Shore A O-Ring supplied with an inside diameter of 11.984 in (304.39 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 12.262 in (311.45 mm). This o-ring provides a reliable static or dynamic seal by deforming into its gland under assembly load.

The compound resists propane and butane, greases and lubricants, and many alcohols. That behavior comes from the compound itself: Buna-N (Nitrile) is known for the most widely specified general-purpose sealing elastomer and low compression set under sustained load. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). It should not be specified for service in automotive brake fluid or ozone and direct sunlight.

Typical settings include agricultural equipment, general industrial maintenance, and construction equipment.

Reference part number H90278 when ordering; the item is sold individually. Unit weight is approximately 13.2253 g. As always, verify media compatibility and operating conditions against the requirements of your specific application.