Welding symbol
reference guide
Every welding symbol from both major standards, explained in plain English with clear diagrams. Built for welders, fabricators, and engineers who need a quick, reliable reference on the shop floor.
Browse by category
47 symbols across 6 categories
Butt welds
Full or partial penetration welds joining two members aligned in the same plane. Includes square, V, bevel, U, J, and flare preparations.
Fillet welds
Triangular cross-section welds joining surfaces at an angle, typically 90 degrees. The most common weld type in structural fabrication.
Plug & slot welds
Welds made through circular holes or elongated slots to join overlapping members.
Spot & seam welds
Resistance and fusion welds joining overlapping sheets at discrete points or continuous seams.
Edge, overlay & special welds
Edge welds, overlay (surfacing) welds, stud welds, stake welds, and flanged joint welds.
Supplementary symbols
Modifiers added to elementary symbols: contour (flush, convex, concave), field weld, weld-all-round, backing, and more.
Most common symbols
The symbols you'll encounter most in structural and general fabrication work.
International standard
Used across the UK, EU, and most of the world. Features the dual reference line (System A) and explicit throat/leg notation with a/z prefixes.
American standard
Dominant in North America. Uses a single reference line and assumes leg size for fillets without prefix. Arrow side = below the line.