<![CDATA[The selection of the type of welding is determined based on the type of steel, the tensile strength which is influenced by the carbon content, and the shielding gas used to minimize the occurrence of welding defects. The effect of large/small gas flowrate on Metal Active Gas (MAG) welding has an effect on the quality of welding results and welding defects. This study aims to determine the effect of gas flow rate MAG welding on tensile strength, hardness and welding defects in ASTM A53 steel. This research is a laboratory experimental study of variations in gas flow rate of MAG welding and then tested for tensile strength with a tensile tester, testing for hardness with a Rockwell harness test, testing for welding defects using a liquid penetrant test. Welding tensile strength based on the average value of the highest modulus of elasticity (E) is the specimen with MAG welding treatment with a gas flow rate variation of 25 liters/minute, which is 22.04 N/. The hardness value of the weld metal shows the highest average HRB value in MAG welding with a gas flow rate variation of 25 liters/minute which has an average value of 86.06 HRB. The metal hardness value in the Heat Affected Zone shows the highest average HRB value in MAG welding with a gas flow rate variation of 25 liters/minute which has an average value of 84.65 HRB, the hardness value in the base metal area shows the highest average value in MAG welding with a gas flow rate variation of 25 liters/minute which has an average value -average 82.92 HRB. The results of the welding defect test show that for all variations of the types of welding defects that arise are porosity, undercut, lack of penetration and spatter]]>
