Weld symbols for commonly used welds

Weld symbols for commonly used welds

Weld symbols for commonly used welds

Fillet Weld

A Fillet Weld is the joining of two metal pieces together perpendicular or at an angle.

·         Fillet weld symbol: The figure below shows the weld symbol for a fillet weld and which side of the line the details of the weld should be on. If the leader is on the same side as the desired weld, it will be on the bottom of the line. If the weld is required on the alternative side, the weld detail will be above the line.


·         Different Weld lengths on either side


·         Unequal Weld lengths


·         Fully Welded Symbol



·         Stitch Welding




Butt Weld

A butt weld is welding two plates together end to end on the same plane without any overlap. Below are some types of Butt joints and the symbol for each Butt joint weld.

·         Square Butt Joint Weld

·         V-Joint Butt Weld

·         U-Joint Butt Weld

·         J-Joint Butt Weld



Double sided Butt Weld



Plug Weld/Slot Weld

A plug/slot weld is joining of two metal sheets together by depositing the weld in the hole of one of the sheets. It normally involves 2 sheets overlapping each other with the hole/slot being filled on the top sheet. The hole/slot is completely covered with weld.

Below is an example of the plug and slot weld symbol.

       ·         Diameter of the weld is on the left of the symbol

      ·         The spacing distance (plug to plug) is given on the right

      ·         The number of plugs/slot welds is given below the symbol in brackets



Displaying Weld Symbols on Drawings

Weld symbols don’t have to be shown on every weld on the drawing. A simple note can be shown in the notes of the drawing to describe what the weld needs to be. Below are example of notes which can be used.

EXAMPLE Note: Unless otherwise designated, all welds are to be made in accordance with Specification xxxx

EXAMPLE NOTE: Unless otherwise indicated, all fillet welds are xXXx mm in size

EXAMPLE NOTE: unless otherwise indicated, root gaps for all butt welds are xXXx mm

For all weld symbol standards and requirements, refer to SAI Global website for the latest version of the standard. The Australia Standard Graphical symbols for general engineering: Welding and non-destructive examination is AS1101.3. 

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