ABSTRAKThe research aims to determine the geometrical effect of weld joint towardsresidual stress, natural frequency, also micro and macro structure changes inshaft material AISI 1020. Material used as shaft is low carbon steel AISI 1020,diameter 40 mm. SMAW weld method used to merge the shaft using E6013electrode, diameter 3.2 mm. The specimen has two types of seam welds, Double VGroove and Double Bevel Groove, with variation 20°, 22.5°, and 30° tilt angle.The residual stress measuring result in the axial direction obtain highest value ofresidual stress at point 0 mm on Double Bevel Groove weld seams with 30° tiltangle, also at point 5, 10, 15, and 25 mm in Double V Groove sample with 30° tiltangle. Residual stress measured in the hoop direction obtained highest residualstress value at point 0 Double V Groove with 22.5° tilt angle, than point 10, and25 mm in Double Bevel Groove with 30° tilt angle, and in point 5, and 15 mm inDouble V Groove with 30° tilt angle. Natural frequency testing generate highestvalue at point 35 and 95 mm from the accelerometer on the Double Bevel Groovesample with 30° tilt angle, and point 65 mm at the Double V Groove sample with30° tilt angle.Keywords : Weld Joint, Residual Stress, Natural Frequency