The H4X128 is a black Buna-N (Nitrile) 70 Shore A O-Ring built to an inside diameter of 128 mm (5.039 in), a cross section of 4 mm (0.157 in), and an outside diameter of 136 mm (5.35 in). This o-ring compresses into its gland to block fluid or gas migration across a joint.
This material stands up to water, petroleum-based oils, and many alcohols. Buna-N (Nitrile) offers an economical choice for high-volume maintenance programs 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. It should not be specified for service in automotive brake fluid or ketones.
You will find this material specified across hydraulic and pneumatic systems, general industrial maintenance, and automotive.
Order part number H4X128, sold individually. Unit weight is approximately 6.364 g. As always, verify media compatibility and operating conditions against the requirements of your specific application. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
description 4MM CS X 128MM ID BLACK BUNA 70D
uf_description2 METRIC O-RING
Actual_OD 136 mm (5.35 inch)
Actual_CS 4 mm (0.157 inch)
Actual_ID 128 mm (5.039 inch)
ProductCode Description O-Rings - Metric - Commodity