Hydrogenated Nitrile Butadiene Rubber is a type of synthetic rubber that is known for its excellent resistance to heat, oils, and chemicals. HNBR is produced through the hydrogenation process of Nitrile Butadiene Rubber (NBR), which enhances its thermal stability and durability. The hydrogenation process saturates the double bonds in the polymer chain, reducing susceptibility to aging, ozone degradation, and environmental factors. This unique composition of HNBR makes it particularly suitable for timing belts, which operate under high stress and demanding conditions.