-138 BLACK BUNA 70D O-RING

H70138 is an AS568-138 black Buna-N (Nitrile) 70 Shore A O-Ring supplied with an inside diameter of 2.112 in (53.64 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 2.318 in (58.88 mm). In service, this o-ring compresses into its gland to block fluid or gas migration across a joint.

It resists petroleum-based oils, many alcohols, and hydraulic fluids. That behavior comes from the compound itself: Buna-N (Nitrile) is specified for strong abrasion and tear resistance, an economical choice for high-volume maintenance programs. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Applications involving ozone and direct sunlight or ketones call for a different compound.

You will find this material specified across hydraulic and pneumatic systems, construction equipment, and automotive.

Order part number H70138, sold individually. Unit weight is approximately 0.0012 g. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.