Angular distortion has an effect not only on the weld quality but also on the size and dimension accuracy. The amount of angular distortion is affected by the welding heat input and the flange thickness (h). This research was conducted to analyze the influence of welding heat input (welding current and speed were varied)on the angular distortion in T weld joint of mild steel plate of SS 400 with various thicknesses welded by SMAW. Distortion is obtained from the deflection measured by the dial gauge. The result shows an increase in the number of weld layers for plates of 6 mm and 10 mm causes an increase in the measured deflection (angular distortion). On the plate of 2 mm due to its lack of rigidity, buckling distortion took place, which added the amount of measured deflection. It was found that an increase in the welding heat input causes an increase in the distortion. It goes to maximum when critical value ofx – 0.4-0.5 is reached. Based on analysis of variance (ANOVA), at significance level (a) = 5%, the factor that has significant effect on the amount of angular distortion is the flange thickness.
