The FSW solid weld joint method can be used to joint several radius joints, which will be investigated for the strength of welded joints with 6061 aluminum material. with a size of 100 mm x 250 mm and a thickness of 5 mm, cut into a radius of 700mm, 900mm, 1000 mm, 1100mm, 1200 mm, and 1500 mm. The butt joint is joined by the friction stir welding (FSW) method using a milling machine. This experiment was carried out manually using universal milling with good results, it can be applied to modern machine buildings. The microstructure of the good results did not occur defects and manganese formed small balls in the FSW with a radius of 700 mm, the highest hardness test results occurred in the FSW with a radius of 1100 mm, namely 45 VHn, and the highest tensile strength occurred at a radius of 700 mm, which was 92 MPa.