Friction welding is one of the solid-state welding processes that is capable of producing high quality joints for dissimilar materials. This study aims to determine the effect of pressure and welding time on the physical and mechanical properties of friction welding joints of AISI 316 and AISI 4140. The physical are microstructure on interface joint and dimension of flash was investigated. The variation of friction pressure used is 50 kg/cm2, 70 kg/cm2 and 90 kg/cm2, while the time variations used are 35 seconds, 50 seconds and 65 seconds. The results of this study indicate that the greater the friction pressure and friction time applied, the greater the tensile strength achieved is 381.50 N/mm2. The effect of increasing friction pressure variations can reduce the value of weld joint hardness, but conversely if the friction time increases, the hardness value in the weld joint area will also increase. It was proven that in the variation of the minimum friction pressure the hardness achieved was 530.5 VHN but the maximum friction pressure variation only reached 352.2 VHN. The microstructure test show that phase transformation occurs which results in different grains from the parent metal area.