[ WELDING SYMBOLS · STANDARD ]
AWS A2.4 welding symbols
AWS A2.4 is the American Welding Society standard for welding symbols, used on US drawings and on projects built to AWS codes such as D1.1. Its key rule: a weld symbol below the reference line is on the arrow side, above the line on the other side.
- Full title
- AWS A2.4, Standard Symbols for Welding, Brazing, and Nondestructive Examination
- Current edition
- AWS A2.4:2020
- Published by
- American Welding Society
- Arrow side
- Below the reference line. Other side above
- Sizes
- Fillet leg size by default, written to the left of the symbol; length and pitch to the right
- Processes
- Letter designations from AWS A3.0, such as SMAW, GMAW, GTAW, written in the tail
Groove welds AWS A2.4
About groove welds- Square groove weldSquare butt weld
- V groove weldSingle-V butt weld
- Bevel groove weldSingle-bevel butt weld
- U groove weldSingle-U butt weld
- J groove weldSingle-J butt weld
- Flare-V groove weldFlare V butt weld
- Flare-bevel groove weldFlare bevel butt weld
- Double-V groove weldX weld
- Double-bevel groove weldK weld
- V groove with broad root faceY weld
Fillet, plug, spot and seam welds AWS A2.4
About fillet, plug, spot and seam weldsSupplementary symbols AWS A2.4
About supplementary symbolsParts of a welding symbol AWS A2.4
About parts of a welding symbolThe AWS rules in short
- One reference line, no dashed line. Below the line means the arrow side, above means the other side, on both sides means both.
- The perpendicular leg of fillet, bevel and J symbols is always drawn on the left.
- Size to the left of the symbol, length and pitch to the right, root opening inside, groove angle beside it.
- A break in the arrow points to the member that is bevelled or prepared.
- The tail carries the process, the procedure or a note, and is left off when not needed.
- Nondestructive examination uses its own symbols on the same reference line, with letters such as VT, PT, MT, RT and UT.
See how to read welding symbols for sizes, the tail and a worked example, and AWS vs ISO for the differences from ISO 2553.
About this legend
The drawings here follow the forms in AWS A2.4. The standard itself has more detail, such as brazing and nondestructive examination symbols, and the drawing notes of each project take precedence.
Frequently asked questions
What is AWS A2.4?
The American Welding Society standard for welding, brazing and nondestructive examination symbols on drawings. The current edition is AWS A2.4:2020.
Which side is the arrow side in AWS?
A weld symbol below the reference line is on the arrow side. Above the line is the other side.
How is a fillet weld sized in AWS?
By its leg size, written to the left of the triangle. A second number in brackets can give the effective throat.
What goes in the tail of an AWS welding symbol?
The welding process, using AWS A3.0 letters such as SMAW or GMAW, a procedure (WPS) number, or a reference to a note.
- In production since 2014
- Thousands of daily users
- On MODEC FPSO projects since 2016
The symbols on this page were drawn by Deskely and are free to use. Standards are revised and every project issues its own legend sheets, which take precedence.