4MM CS X 66MM ID BLACK BUNA 70D

APG stocks the H4X66, a black Buna-N (Nitrile) 70 Shore A O-Ring built to an inside diameter of 66 mm (2.598 in), a cross section of 4 mm (0.157 in), and an outside diameter of 74 mm (2.91 in). An o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.

This material stands up to propane and butane, hydraulic fluids, and water. That behavior comes from the compound itself: Buna-N (Nitrile) delivers strong abrasion and tear resistance, low compression set under sustained load. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where ketones or automotive brake fluid are present.

It sees regular use in construction equipment, fluid power, and agricultural equipment.

Reference part number H4X66 when ordering; the item is sold individually. Unit weight is approximately 3.4273 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.