Many factors need to be taken into consideration, so this is difficult to answer. What is the mold used for and with what casting medium? How large is the mold, the severity of undercuts in the mold? How is it stored? As well as the type of silicone used. Yields can vary from 10 parts to hundreds of parts. Average mold life expectancy for urethane cast pieces average between 30-70 pulls depending on all the factors involved.