Ordered as H3X15.5, this is a black Buna-N (Nitrile) 70 Shore A O-Ring with an inside diameter of 15.5 mm (0.61 in), a cross section of 3 mm (0.118 in), and an outside diameter of 21.5 mm (0.85 in). The o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.
This material stands up to hydraulic fluids, water, and greases and lubricants. That behavior comes from the compound itself: Buna-N (Nitrile) delivers the most widely specified general-purpose sealing elastomer and low compression set under sustained load. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Applications involving strong acids or ketones call for a different compound.
It sees regular use in automotive, construction equipment, and hydraulic and pneumatic systems.
Stocked as H3X15.5 and sold individually. Unit weight is approximately 0.4991 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
description 3MM CS X 15.5MM ID BLACK BUNA 70D
uf_description2 METRIC O-RING
Actual_OD 21.5 mm (0.85 inch)
Actual_CS 3 mm (0.118 inch)
Actual_ID 15.5 mm (0.61 inch)
ProductCode Description O-Rings - Metric - Commodity