Nitrile rubber (NBR, also called Buna-N) is the most widely used sealing elastomer in the oil and gas industry, and for good reason. It offers excellent resistance to petroleum-based oils, fuels, hydraulic fluids, water, and many drilling and completion fluids, combined with good abrasion resistance, low compression set, and strong mechanical properties at a cost-effective price. Moss Seal supplies NBR in a range of hardnesses and acrylonitrile (ACN) contents: higher ACN grades maximize oil and fuel resistance, while lower ACN grades improve low-temperature flexibility. NBR is typically suited to service from roughly -30°F to 250°F (-34°C to 121°C), depending on grade. For higher temperatures, sour gas, or aggressive chemicals, we recommend stepping up to HNBR or FKM.