4MM CS X 21MM ID BLACK BUNA 70D

The H4X21 is a black Buna-N (Nitrile) 70 Shore A O-Ring with an inside diameter of 21 mm (0.827 in), a cross section of 4 mm (0.157 in), and an outside diameter of 29 mm (1.14 in). This o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.

It resists many alcohols, hydraulic fluids, and greases and lubricants. Buna-N (Nitrile) offers an economical choice for high-volume maintenance programs, strong abrasion and tear resistance. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. It is not the right choice where automotive brake fluid or strong acids are present.

You will find this material specified across construction equipment, automotive, and general industrial maintenance.

Reference part number H4X21 when ordering; the item is sold individually. Unit weight is approximately 1.3 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.