Standard Welding Symbols – Changes to AWS A2.4:2020

Worker joining metals in building weld while following AWS A2.4:2020 for standard welding symbols.

Standard welding symbols facilitate communication from the designer to fabrication (“welders”) and inspection personnel. To the common observer, these symbols may appear as cryptic shapes in meaningless formations. However, to the 425,000 welders, cutters, solderers, and brazers working in the U.S. and industry professionals worldwide, these symbols, thanks to AWS A2.4:2020 – Standard Symbols For Welding, Brazing, And Nondestructive Examination, convey clear, harmonized instructions.

About Welding Symbols and AWS A2.4:2020                                    

A welding symbol is the graphical representation of the specifications for producing a welded joint, and, while the horizontal reference line and arrow are required, the symbol can consist of several elements. The “arrow side” is the side of the joint to which the arrow of the welding symbol points, and the “other side” is the side of the joint opposite the arrow side. Weld symbols (not welding symbols) are connected the reference line to specify the joint geometry or weld type. For designating supplementary information, the tail of the welding symbol and supplementary symbols can be used.

AWS A2.4:2020 establishes the method for specifying certain welding, brazing, and nondestructive examination information through these symbols with conventions for specifying the location and extent of their application.

As depicted with illustrations, AWS A2.4:2020 details examples for the construction and interpretation of symbols for groove welds, fillet welds, plug welds, slot welds, spot welds, seam welds, edge welds, stud welds, and surfacing welds and symbols for brazing and nondestructive examination.

Changes to AWS A2.4:2020

While the AWS A2.4 American National Standard was first published in 1976, it began as a consolidation of AWS A2.0, Standard Welding Symbols, and A2.2, Nondestructive Testing Symbols, two documents that had been in existence for decades.

AWS A2.4:2020 revises the previous edition of the standard for welding symbols from 2012. In total, this eighth edition marks a sizable revision, and its notable changes include:

  • The standard now details usage for flare groove welds.
  • The diameter symbol, Ø, is no longer a part of the plug weld symbol. However, users should note that this symbol is still needed when designating the plug dimension on the welding symbol.
  • The contour of the weld is now allowed to be achieved by any method (e.g., welding or mechanical) as seen fit at the work site. The flat contour symbol is now limited to fillet welds, while the flush symbol is used for other welds, such as groove, plug, and slot.
  • Combination groove weld symbol designating two different edge shapes. This is a major change in which one groove weld symbol may be drawn backward (e.g., flare bevel and bevel) to demonstrate actual configuration of the weld joint.
  • The use of multiple subreference lines is now allowed to designate a groove weld extending around a joint where there is no clear point where the joint transitions from one joint type to another.
  • The ability to designate size or strength by placing a value to the left of a spot and seam welds weld symbol has been modified. The dimension to the left of the weld symbol will only designate the size of the weld.
  • Flash and upset welding symbols are no longer supported.
  • Figures now have new number designations to reflect the clause in which they are referenced.
  • The clause for the symbol for nondestructive examination has been rewritten and expanded.

For the aid of the user, any change to AWS A2.4:2020 from the previous edition is underlined in the document’s text or noted through vertical lines in the margin next to the figures.

AWS A2.4:2020 – Standard Symbols For Welding, Brazing, And Nondestructive Examination is available on the ANSI Webstore. For further support and guidance, it can also be acquired as part of the following standards packages, which bundle it with other related standards:

AWS BUNDLE A:2010 – AWS D1.1 / AWS A2.4 / AWS A3.0M

AWS BUNDLE C:2010 – AWS A2.4 and AASHTO/AWS D1.5M/D1.5

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