1.78MM CS X 173.87MM ID BLACK BUNA 70D

H1.78X173.87 is a black Buna-N (Nitrile) 70 Shore A O-Ring with an inside diameter of 173.87 mm (6.845 in), a cross section of 1.78 mm (0.07 in), and an outside diameter of 177.43 mm (6.99 in). In service, this o-ring delivers dependable bidirectional sealing in a compact groove envelope.

As a material, Buna-N (Nitrile) is known for strong abrasion and tear resistance, the most widely specified general-purpose sealing elastomer. The compound resists hydraulic fluids, petroleum-based oils, and greases and lubricants. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Exposure to ozone and direct sunlight or automotive brake fluid will shorten service life.

Maintenance and OEM teams specify it across agricultural equipment, hydraulic and pneumatic systems, and general industrial maintenance.

Reference part number H1.78X173.87 when ordering; the item is sold individually. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.