-309 BLACK BUNA 90D O-RING

This Buna-N NBR 90A O-Ring, item H90309, is designed for buyers who need a clear specification match for industrial fluid sealing, equipment repair, pumps, valves, cylinders and general maintenance applications. The item is specified by AS568-309; 0.412 inch (10.46 mm) ID x 0.21 inch (5.33 mm) CS; 0.832 inch (21.13 ) OD, with 7/16 inch nominal ID; 3/16 inch nominal CS for cross-reference against common gland and replacement dimensions. Its Buna-N nitrile (NBR) material provides 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. This standard industrial O-ring can be used across compatible static and dynamic sealing applications in pumps, valves, cylinders and assemblies. The each-unit format supports precise replacement, kitting, resale and job-specific purchasing. Common purchasing identifiers for this product include the material name, O-ring type, dimensional size, hardness and intended sealing application. Those attributes make the item easier to compare for maintenance, OEM production, MRO replacement and reseller catalog use.