3.1MM CS X 104.4MM ID BLACK BUNA 90D

Ordered as H90M3.1X104.4, this is a black Buna-N (Nitrile) 90 Shore A O-Ring measuring an inside diameter of 104.4 mm (4.11 in), a cross section of 3.1 mm (0.122 in), and an outside diameter of 110.6 mm (4.35 in). The o-ring seats in a machined groove and forms a leak-tight barrier when compressed between two mating surfaces. Source specification: Metric O-RING, JIS G105.

This material stands up to water, hydraulic fluids, and petroleum-based oils. That behavior comes from the compound itself: Buna-N (Nitrile) is known for reliable performance in both static and dynamic service, strong abrasion and tear resistance. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Exposure to polar solvents or ketones will shorten service life.

Maintenance and OEM teams specify it across fluid power, hydraulic and pneumatic systems, and automotive.

H90M3.1X104.4 ships individually. Unit weight is approximately 3.512 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.