  To reduce tear and wear of machinery lubrication is essential. Lubricants
form a layer between two surfaces preventing direct contact and reduce friction
between moving parts and hence reduce wear. In this short letter the
lubrication of two slider bearings with parallel and nonparallel is studied.
First, we show that bearings with parallel plates cannot support any load. For
bearings with nonparallel plates we are interested on how constant and
temperature dependent viscosity affects the properties of the bearings. Also, a
critical temperature for which the bearings would fail due to excess in
temperature is found for both latter cases. If the viscosity is constant, the
critical temperature is given by an explicit formula, while for the
non-constant viscosity the critical temperature can be always found from a
closed form formula involving Weber functions
