-349 BLACK BUNA 70D O-RING

Part number H70MD349 is an AS568-349 black Buna-N (Nitrile) 70 Shore A O-Ring measuring an inside diameter of 4.475 in (113.67 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 4.895 in (124.33 mm). An o-ring seats in a machined groove and forms a leak-tight barrier when compressed between two mating surfaces.

Buna-N (Nitrile) is known for strong abrasion and tear resistance, low compression set under sustained load. It resists greases and lubricants, petroleum-based oils, and hydraulic fluids. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Exposure to automotive brake fluid or polar solvents will shorten service life.

The compound is metal detectable for HACCP and foreign-body control programs. You will find this material specified across construction equipment, general industrial maintenance, and fluid power.

Stocked as H70MD349 and sold individually. 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.