Ordered as H90418, this is an AS568-418 black Buna-N (Nitrile) 90 Shore A O-Ring built to an inside diameter of 3.6 in (91.44 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 4.15 in (105.41 mm). The o-ring provides a reliable static or dynamic seal by deforming into its gland under assembly load.
The compound resists water, hydraulic fluids, 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 and low compression set under sustained load. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Applications involving ketones or automotive brake fluid call for a different compound.
Common environments for this compound include general industrial maintenance, automotive, and fluid power.
This item is sold individually under part number H90418. Unit weight is approximately 15.4 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
description -418 BLACK BUNA 90D O-RING
uf_description2 0.275" (6.99MM) CS X 3.600" (91.44MM) ID
Actual_CS 0.275 inch (6.99 mm)
Actual_ID 3.6 inch (91.44 mm)
Actual_OD 4.15 inch (105.41 mm)
ProductCode Description O-Rings - Bulk - Commodity