Every weld symbol element explained — reference line, arrow side, other side, weld-all-around, field weld, and tail. Covers all weld types per AWS A2.4. Free reference for fabricators, welding engineers, and CWIs.
Welding Symbol Anatomy
①Weld-all-around — circle at arrow junction. Weld goes completely around the joint.
②Arrow — points to the joint. Arrow-side = same side as arrow.
③Other side — symbol above the reference line. Weld on opposite side from arrow.
④Arrow side — symbol below the reference line. Weld on same side as arrow.
⑤Field weld flag — filled flag at the arrow junction. Weld made on-site, not in shop.
⑥Tail — V-shape at right end. Contains process, specification, or procedure notes.
G (grind), M (machine), C (chip), H (hammer), P (planish), R (roll), U (unspecified) — per AWS A2.4:2020
Tail
Right end of reference line
Specification, process, or note — e.g. SMAW, AWS D1.1, or WPS number
Weld-all-around
Circle at arrow junction
Weld completely around the joint — all sides, no breaks
Field weld
Filled flag at reference line
Weld on-site during erection, not in the fabrication shop
CJP
In tail or note
Complete Joint Penetration — weld fuses full thickness of joint
PJP
In tail or note
Partial Joint Penetration — groove depth less than full thickness
Common Questions
Weld Symbol FAQ
What is a weld symbol?
A weld symbol is a standardized graphical notation placed on engineering drawings to specify the type, size, location, and extent of a weld. Weld symbols follow AWS A2.4 (North American standard) or ISO 2553 (international standard). They consist of a reference line, arrow, weld symbol, and optional tail containing process or specification notes.
What is the difference between a weld symbol and a welding symbol?
A weld symbol (lowercase) refers specifically to the small graphic indicating weld type — for example, a right triangle for a fillet weld. A welding symbol (capitalized) refers to the complete assembly including the reference line, arrow, weld symbol, dimensions, and tail. The distinction matters when reading complex drawings with multiple elements.
What does arrow side and other side mean?
The reference line divides the welding symbol into two sides. The arrow side (symbol below the reference line) specifies the weld on the same side as the arrow points to on the joint. The other side (symbol above the reference line) specifies a weld on the opposite side of the joint. When both sides show a symbol, weld both sides.
What is the circle on a weld symbol?
A small circle at the junction of the reference line and arrow is the weld-all-around symbol. It indicates the weld must be made completely around the joint — for example, all four sides of a tube-to-plate connection or the full perimeter of a pipe penetration. Per AWS A2.4, the circle is placed at the junction of the reference line and arrow.
What does the flag on a weld symbol mean?
A filled triangle (flag) at the reference line / arrow junction is the field weld symbol. It indicates the weld must be made in the field during erection — not in the fabrication shop. This distinction is critical for structural steel projects. Shop welds are completed before delivery; field welds are completed on-site. Different inspectors, different QC requirements.
What does G mean on a weld symbol?
The letter G placed above a contour symbol means grind — the completed weld face must be ground smooth to the specified contour. Other finishing designators per AWS A2.4:2020: M = machine, C = chip, H = hammer, P = planish, R = roll, U = unspecified. These appear above or below the weld symbol depending on side. See full explanation of the G finishing symbol.
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