A large segment of the oil and gas drilling industry relies on acrylonitrile butadiene rubber (NBR) compounds for producing critical parts like pumps, blow-out preventers, and stator assemblies. The trend in the oiVgas industry is toward drilling increasingly deeper wells. At greater well depths, the environmental conditions that rubber-to-metal bonded components are exposed to become more extreme. The bonded assemblies must resist oils, acids, salt brine, and drilling muds at temperatures exceeding 121*lC. These harsh environmental conditions are moving the industry from NBR to hydrogenated acrylonitrile butadiene rubber (HNBR), a specialty elastomer having excellent high temperature and fluid resistance. This trend necessitated the development of adhesives to match the increased performance achieved with HNBR compounds. LORD Chemlok@ 6450 and 6451 adhesives were developed and tested with a wide variety of HNBR and NBR elastomers in demanding environmental conditions. Performance was evaluated in ASTIVI International fuels, elevated temperature ASTIVI International oils, boiling water, acid, salt brine and diesel-based drilling mud. Both adhesives deliver enhanced performance in challenging conditions and offer new options to meet the current industry trends.