3.5MM CS X 77MM ID BLACK BUNA 70D

Part number H3.5X77 is a black Buna-N (Nitrile) 70 Shore A O-Ring built to an inside diameter of 77 mm (3.031 in), a cross section of 3.5 mm (0.138 in), and an outside diameter of 84 mm (3.31 in). An o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.

It resists water, greases and lubricants, and petroleum-based oils. That behavior comes from the compound itself: Buna-N (Nitrile) is known for the most widely specified general-purpose sealing elastomer, strong abrasion and tear resistance. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Verify compatibility before use with automotive brake fluid or ozone and direct sunlight.

Maintenance and OEM teams specify it across hydraulic and pneumatic systems, construction equipment, and automotive.

Order part number H3.5X77, sold individually. Unit weight is approximately 2.97 g. Application requirements vary, so validate compatibility with your process conditions prior to installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.