When making edge-to-edge joints, you'll most likely use a groove weld. Welders might also use it in corner joints, T joints and joints between curved and flat pieces. As suggested by the variety of groove weld symbols, there are many ways to make a groove weld. The differences depend primarily on the geometry of the parts to be joined and the preparation of their edges. Operators deposit weld metal within the groove, which penetrates and fuses with the base metal to form the joint.
(Note: For the sake of graphical clarity, the drawings below generally do not show the penetration of the weld metal. Recognize, however, that the degree of penetration is important in determining the quality of the weld.)