Edge along each side of a weld bead where weld metal meets the surface of the base metal. Toes are the main stress concentration in a welded joint, so undercut, overlap and sharp toe angles there drive fatigue cracking. Fatigue-critical welds are sometimes toe-ground or peened to smooth the transition and extend life.
Undercut at the top toe is over a thirty-second, dress it with a stringer before you call for inspection.
Also heard as
- weld toe
- toes
Related terms
Undercut
A notch the arc melts into the base metal beside the weld toe that the weld metal never fills back in.
Cold lap
Shop term for weld metal that rolls over onto the base metal or a previous bead without fusing to it.
Fillet weld
Weld with a triangular profile laid in the corner where two members meet, the usual weld on T, lap and corner joints.
Cap
Shop word for the final layer of passes on the face of a groove weld, the cover pass in code language.