.312" C/S (5/16") (8 MM)

Use item 0284H312 when a Buna-N NBR 90A O-Ring Cord is required for custom O-ring fabrication, spliced seals, field repairs and nonstandard groove diameters. The item is specified by 0.312 inch (8 mm) cross section, with 5/16 inch nominal CS for cross-reference against common gland and replacement dimensions. The Buna-N nitrile (NBR) construction supports oil, grease, fuel and general hydraulic fluid resistance in common industrial equipment. It is with a listed temperature range of -40°F (-40°C) to 250°F (121°C), which can help narrow material selection for heat, cold or process exposure. The black color and round profile provide a practical visual identifier during receiving, stocking and installation. As O-ring cord, it gives fabricators flexibility to cut and splice seals when a molded size is not practical or available. It is sold as cord stock, making it useful for fabricating custom O-rings or replacement seals in nonstandard diameters. Important product identifiers include O-rings, replacement seals, fluid sealing, material compatibility and dimensional fit. It supports customer comparison, distributor cataloging and specification-based selection without relying on pricing, availability or shipping claims.