The present work aims to estimate channel, shell, tube and tube sheet stresses of shell and tube oil cooler stemmed from various parameters. These parameters involve size, thickness and dimension of shell and tube oil cooler, including fluid temperature. The main purpose of the present work is to ensure safety of design products and also develop new products rapidly. For stress evaluation of oil coolers, first of all, the maximum pressure on the shell-side and on the tube side is fixed with 3.1MPa and 1.5MPa, respectively. Secondly, the pressure on each side varies from 2MPa to 3.1MPa on the shell side and tram 0.6MPa to 2MPa on the tube side. Various parameters under these conditions are employed to estimate design stresses on each side of oil cooler. These basic information related to stresses will be useful for a designer or manufacturer of an oil cooler.