The single “V” butt weld is used in joining sheets, where only one side of the sheet to be welded is
accessible.
The edges of the sheet to be welded are beveled to an included angle of 600. A root gap of approximately
1/32 to 1/64 of an inch is left between the joining sheets to insure full weld penetration. In making a single
“V” butt weld, the first pass is made a the bottom of the weld-bed, after tacking. Passes are then made
along the edge of first one sheet and then the other so that the weld is built up evenly. If the back area of
a single “V” butt weld is accessible, a single bead on the back will provide additional strength for this type
of weld. When using 1/8 inch material, one 3/16 inch rod will usually fill the “V” and overlap the edges. For
3/16 inch material, the first bead should be laid with 1/8 inch rod, and for a good overlap, two additional
beads, of 5/32 inch rod, will give maximum strength.
Note: A single “V” weld, reinforced with a 1/8 inch rod pass on the other side will be usually stronger than
a double “V” butt weld.