This study aims to determine the tensile strength, hardness of steel joints with copper using the FSW method. Material used st37 steel, copper. in the welding process using a conventional milling machine with rotational rotation of 800 rpm and 1250 rpm, feed rate 12.5 mm / min, slope angle 10 and 1.8 mm plunge dept. using the ASTM E8M testing standard for tensile testing and ASTM E384 standard for violent testing. From the tensile strength test of Fe-Cu connections round 800 rpm has an average voltage of 320.63 Mpa and an average strain of 2.07%, while the 1250 rpm Fe-Cu connection has an average voltage of 165.28 MPa and an average strain - average 1.33%. For base metal at Fe-Cu 800 rpm Fe material has an average stress of 318.01 Mpa and an average strain of 7.62%, while Cu material has an average voltage of 388.26 MPa and an average strain of 13, 27%. For base metal at 1250 rpm Fe-Cu connection Cu material has an average voltage of 388.26 MPa and an average strain of 13.27%, while Fe material has an average voltage of 303.36 Mpa and an average strain of 9 , 46%. From the results of testing the hardness of Fe-Cu connection of rotation of 800 rpm at the stir zone area showed 270,8 HVN value and HAZ area showed 296,2 HVN value, while at 1250 rpm Fe-Cu connection at stir zone area showed 250,3 HVN and the HAZ area shows a value of 270.1 HVN. For base metal Fe-Cu 800 rpm connection in Fe material showed value of 162,4 HVN and Cu material showed 73,1 HVN value, while for base metal connection at Fe-Cu 1250 rpm Fe material showed 162,2 HVN value and material Cu shows a value of 74.2 HVN.
Keywords: friction stir welding, st37 steel, copper, tensile, hardness. Spindle
