Nitrile Rubber, frequently referred to as Buna-N, is a copolymer of butadiene and acrylonitrile. A number of polymers are commercially available with various monomer ratios. Those containing a high proportion of acrylonitrile have excellent resistance to petroleum oils and solvents, good tensile strength and abrasion resistance, but relatively poor low temperature flexibility. Decreasing acrylonitrile content yields great imrovement in the low temperature capability, but at the expense of poorer oil resistance. The most useful compounds are based on medium grades which effect a good balance of properties. Because of the generally good characteristics and a capability for being compounded to obtain a wide spectrum of specific properties, compounds of nitrile rubber find wide application in mechanical rubber goods.