Resistance spot welding is frequently used welding method in a mass production like: electric industry, production of white goods and production of body assembly in automotive industry. Selected welding parameters often cause excessive input, that assure better reliability of full penetrating welds even in the case of deviations of sheet thickness, surface conditions and deviations of electrode tips due to heat and mechanical damage influences. Excessive energy inputs lead to excessive heating of welded material that can cause unwanted expulsions and electrode tips damages. It shows up that in such cases we get unwanted surface appearance of welded pieces at excessive energy consumption with negative environmental influence and more expensive process.