This study aimed to investigate the effects of weld groove variations and welding current on the tensile strength and microstructure of medium carbon steel joints using FCAW (Flux-Cored Arc Welding). The researcher employed a quantitative approach with an experimental method. The specimens used in this research include FCAW with V-groove and 90 A current, FCAW with V-groove and 70 A current, FCAW with X-groove and 70 A current, FCAW with X-groove and 90 A current, raw material specimens, and microstructure specimens. The data analysis reveals that the highest average tensile stress value among the welded specimens was 463.50 MPa, observed in the FCAW X-groove with 90 A current specimen, while the FCAW V-groove with 70 A current specimen showed the lowest value at 295.1 MPa. Regarding the strain values, the FCAW X-groove with 90 A current specimen had the lowest average strain of 4.15%, whereas the FCAW V-groove with 70 A current specimen had the highest at 5.36%. In terms of microstructure, the FCAW V-groove with 70 A current specimen exhibited martensite, pearlite, and ferrite structures in the weld zone, and ferrite and pearlite structures in the heat-affected zone (HAZ) and base metal. For the FCAW X-groove with 90 A current specimen, pearlite and ferrite structures were found in the weld zone, HAZ, and base metal. Keywords: Carbon Steel, Weld Groove, Welding Current, Tensile Test, Microstructure