8-347 BLACK BUNA 90D BACK-UP RING

Ordered as HB90347, this is an AS568-347 black Buna-N (Nitrile) 90 Shore A Back-Up Ring with an inside diameter of 4.225 in (107.32 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 4.645 in (117.98 mm). The back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

As a material, Buna-N (Nitrile) offers strong abrasion and tear resistance, an economical choice for high-volume maintenance programs. The material holds up against propane and butane, hydraulic fluids, and greases and lubricants. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Applications involving automotive brake fluid or polar solvents call for a different compound.

Typical settings include agricultural equipment, construction equipment, and fluid power.

This item is sold individually under part number HB90347. Unit weight is approximately 3.7241 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.