Abstract
The improvement of fatigue life of SAE 1005 steel sheet by high precision grinding and polishing has been investigated. The flat specimens were cyclically loaded by a plane bending fatigue testing machine, with similar levels of mean and alternating stresses. The relation between edge surface roughness and fatigue life has been studied. Grinding process gives a movement of S-N curve to the right, and improves the fatigue strength of the steel under study. The best improvement in fatigue resistance is obtained by polishing, where the fatigue life has been increased by 150% of the fatigue life of specimens prepared from the as-received steel sheet. The fatigue life is considered as the number of cycles to cause failure.