← Back to Bead BoardWelding symbols chart
Searchable reference for every AWS A2.4 welding symbol. Filter by category, search by name or keyword, and see arrow-side vs other-side meanings at a glance. Groove, fillet, plug, slot, spot, seam, and every supplementary symbol in one place.
Quick answer
The fillet weld symbol is a right triangle on the reference line. Below the line means arrow side. Above means other side. It is the most common weld symbol in fabrication.
How to read a welding symbol
Every welding symbol starts with a reference line and an arrow that points to the joint. The weld type goes on the reference line as a shape (triangle for fillet, V for groove, etc.). Dimensions sit next to the shape: size, length, and pitch. Supplementary symbols add instructions like field weld (flag), weld-all-around (circle), or contour. A letter like G or M after the contour tells the fabricator the finish method. The tail at the opposite end calls out the welding process or WPS number.
Three rules cover 90% of reading: symbols below the reference line apply to the arrow side, symbols above apply to the other side, and a broken arrow means it points to the member that gets the bevel or preparation.
Simplified diagram. The fillet triangle below the reference line means “fillet weld on the arrow side.” The tail is omitted when no process or specification is called out.
Dimension callout positions
Where you place a number on the symbol changes what it means. The rules are different for fillets and grooves.
Fillet welds
- Left of symbol = leg size (e.g. 1/4)
- Right of symbol = weld length
- Hyphenated number after length = pitch (center-to-center spacing for intermittent welds)
Groove welds
- Left of symbol = depth of preparation
- Inside the symbol = root opening and groove angle
- Parentheses = effective throat
CJP vs PJP
A CJP (complete joint penetration) groove shows no depth dimension because full penetration is implied. A PJP (partial joint penetration) groove shows the required depth in parentheses to the left of the symbol.
Finish method codes
A letter placed above the contour symbol tells the fabricator how to achieve the required surface profile. The letter specifies the method, not the degree of finish.
Questions welders keep asking
How do you read a welding symbol?
Start at the reference line. The arrow points to the joint. Symbols below the reference line apply to the arrow side (the side the arrow touches). Symbols above the reference line apply to the other side. Read dimensions left to right: size, length, pitch. Check the tail for process or specification callouts. A flag at the junction means field weld. A circle means weld all around.
What does the flag mean on a welding symbol?
The flag (a solid filled pennant at the arrow-reference line junction) means field weld. The weld must be made on-site during erection, not in the shop. You will see this on structural steel prints for connections that cannot be completed until the members are in position.
What is the difference between arrow side and other side?
Arrow side is the side of the joint that the arrow physically points to. Other side is the opposite face. On a welding symbol, information placed below the reference line applies to the arrow side. Information above the reference line applies to the other side. If you see a fillet triangle below and above the reference line, the joint gets fillet welds on both sides.
What is the difference between CJP and PJP?
CJP (Complete Joint Penetration) means the weld fuses through the full thickness of the joint. No depth dimension is shown on the symbol because full penetration is implied. PJP (Partial Joint Penetration) means the weld only fuses part way through, and the required depth is shown in parentheses on the symbol. CJP costs more because it typically requires back-gouging or backing and full-penetration NDE. PJP is cheaper when the design loads allow it.
What goes in the tail of a welding symbol?
The tail contains the welding process designation (like GMAW, SMAW, GTAW), the WPS number, or a specification reference. If no process or specification is needed, the tail is omitted entirely. You might also see NDE requirements, joint class references, or notes pointing to a detail on the drawing.
What does the circle at the arrow junction mean?
The open circle at the junction of the arrow and reference line is the weld-all-around symbol. It means the weld continues around the entire perimeter of the joint. You see this on pipe-to-plate connections, tube-to-tube intersections, and any joint where the weld wraps 360 degrees. Do not confuse it with the field weld flag, which is a filled pennant, not an open circle.
What do the finish method letters mean on a weld symbol?
A letter above the contour symbol tells the fabricator how to achieve the required surface finish. G = grind, M = machine, C = chip, H = hammer, P = planish, R = roll, U = unspecified (the fabricator picks the method). The letter specifies the method, not the degree of finish. If the engineer only cares about the final profile and not how you get there, they use U.
Other tools in the Tack Box
Welding Shop Rate Calculator
What should you charge per hour? Break-even and recommended rate.
Welding Cost Calculator
Cost per inch of weld — labor, filler, gas, and markup by process.
Metal Weight Calculator
Plate, pipe, bar, tube. Steel, aluminum, stainless, brass.
Gas Usage Calculator
Cylinder count and cost for a project. MIG, TIG, flux-core.
Filler Metal Calculator
Pounds of wire or rod for a joint. Spool count and cost.
Job Pricing Calculator
Build a bid from scratch — tasks, materials, overhead, margin.
Welding Settings Chart
Amps, voltage, wire speed by process, metal, and thickness.
Wire & Gas Selection Guide
Which wire and shielding gas for your process and base metal.