Friction welding is one method of welding the type solid state welding where the heat source is caused by two friction metals. With the method of friction welding, two metals with different melting points can be connected. However, the steel pipe material with stainless steel pipes has not found a suitable friction pressure parameter if it is connected with the friction welding method. This study aims to determine the effect of variations in friction pressure on the microstructure, hardness and tensile strength of steel pipe connections with stainless steel pipes using the friction welding method. The material used in this study is the carbon steel pipe ASTM A53 Gr.A with stainless steel pipe ASTM A312 TP304. The parameters used in this study were variations in friction pressure of 25 MPa, 30 MPa 35 MPa, forging pressure of 50 MPa, friction time for 1 second and engine speed of 1000 RPM. The application used in this study is a data logger that serves to read the pressure on the friction welding machine. Then the results of the welding were tested for microstructure, material hardness and tensile strength. The results of microstructure tests show the effect of the friction welding process resulting in changes in microstructure which makes the microstructure of the joints become fine-grained and dense. The farther away from the connection, the more micro grained structure will be. The highest hardness value is in the connection area and the decreasing value of its hardness if it is further away with the connection. The highest average tensile strength of 429.25 MPa reaches 93.2% of the tensile strength of carbon steel pipes and reaches 58.76% of the tensile strength of stainless steel pipes obtained at 30 MPa friction pressure. The lowest average tensile strength of 340.53 MPa reaches 73.94% of the tensile strength of carbon steel pipes and reaches 46.61% of the tensile strength of stainless steel pipes. Parameters recommended for friction welding process steel pipes with stainless steel pipes of 30 MPa.