4MM (.157) BUNA-N O RING CORD 70 DURO

Ordered as 0M284B4, this is a black Buna-N (Nitrile) 70 Shore A O-Ring Cord Stock supplied with a cross section of 0.157 in (4 mm). The o-ring cord stock supports field repair of oversized or non-standard sealing grooves without a special tooling charge.

It resists many alcohols, propane and butane, and petroleum-based oils. That behavior comes from the compound itself: Buna-N (Nitrile) delivers low compression set under sustained load, strong abrasion and tear resistance. Applications involving ozone and direct sunlight or strong acids call for a different compound.

Maintenance and OEM teams specify it across automotive, construction equipment, and general industrial maintenance.

0M284B4 ships by the foot. Check the compound against your process media, pressure and temperature before committing to a design.