This o-ring is supplied in AS568-427 black Buna-N (Nitrile) 90 Shore A supplied with an inside diameter of 4.725 in (120.02 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 5.275 in (133.99 mm), catalogued under part number H90427. It creates a positive seal at flange, piston and rod interfaces without added hardware.
Expect good resistance to hydraulic fluids, water, and petroleum-based oils. That behavior comes from the compound itself: Buna-N (Nitrile) is known for the most widely specified general-purpose sealing elastomer, strong abrasion and tear resistance. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Exposure to strong acids or polar solvents will shorten service life.
You will find this material specified across general industrial maintenance, fluid power, and automotive.
Stocked as H90427 and sold individually. Unit weight is approximately 19.95 g and nominal inside diameter is listed as 4 3/4 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
Description -427 BLACK BUNA 90D O-RING
Actual Cross Section 0.275 inch (6.99 mm)
Actual Inside Diameter 4.725 inch (120.02 mm)
Actual Outside Diameter 5.275 inch (133.99 mm)
Measurement System Imperial
Product Category O-Rings - Bulk - Commodity