Penetration is one of the most important factors that
effects the weld quality of spot weld. The penetration is
the depth to which the nugget extend into the pieces that
are in contact with the electrodes. The minimum depth of penetration is generally accepted as 20% of the thickness
while the depth of penetration should not exceed 80% of
the thickness [1]. Result from this study show that the penetration
of weld found between 20% and 80% of the thickness
of the base metals for all weld currents value.
However, the penetration of the weld was increased by
increasing peak weld current so the tensile shear load bearing
capacity of the weldments were increased.