-257 BLACK BUNA 70D O-RING

The H70MD257 is an AS568-257 black Buna-N (Nitrile) 70 Shore A O-Ring supplied with an inside diameter of 5.859 in (148.82 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 6.137 in (155.88 mm). This o-ring delivers dependable bidirectional sealing in a compact groove envelope.

Buna-N (Nitrile) is specified here for economical choice for high-volume maintenance programs and low compression set under sustained load. It resists water, many alcohols, and petroleum-based oils. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Verify compatibility before use with ketones or strong acids.

This o-ring is metal detectable for HACCP and foreign-body control programs. You will find this material specified across general industrial maintenance, construction equipment, and agricultural equipment.

Reference part number H70MD257 when ordering; the item is sold individually. Nominal inside diameter is listed as 5 7/8 inch. Check the compound against your process media, pressure and temperature before committing to a design.