# Materials Matter: Lambda Ratio

## Surface roughness must be accurately characterized in order for the lambda ratio to be a completely effective tool.

By: Justin Michaud The lambda ratio was originally developed to quantify the quality of lubricant operating regimes relative to bearing performance [1]. Starting around the 1990s, the lambda ratio has been tested and used to define optimal lubricant regimes for gears. In both cases, the lambda ratio has been found to correlate…