As a production engineer and executive, a knowledge of “location of elements of a welding symbols” is necessary for indicating or interpreting. This will now be discussed in more details in the following paragraphs. Any of the following standards could be used depending upon the situation and case of use.
1. AWS-A24: Symbols for welding and non-destructive testing.
2. BS : 499 (Part II): Symbols for welding.
3. ISO : 2553: Symbolic representation on drawings.
4. IS : 813 (1961): Scheme of symbols for welding.
Basic symbols used in ISO and AWS are identical.
In the AWS system a complete welding symbol consists of the following elements:
1. Reference line (always shown horizontally)
3. Basic weld symbol
4. Dimentions and other data
5. Supplemental symbols
6. Finish symbols
8. Specification process or other references.
These elements have specified locations with respect to each other on or around the reference line as shown in Fig. 8.1.
Length of weld
Field weld symbol
Pitch (center-to-center spacing) of welds
Number of spot or projection welds
Arrow connecting reference line to arrow side member of joint
Specification, process or other reference
Basic weld symbol or detail reference
Finish symbol Contour symbol
Root opening; depth of filling for plug and slot welds
Depth of preparation size or strength for certain welds
(Tail omitted when reference is not used)
Elements in this area remain as shown when tail and arrow are reversed
Groove angle; included angle of countersink for plug welds
Weld-all-around symbol Reference line
Fig. 8.1 Standard location of elements on the welding symbol
There are two prevailing systems of placing the symbol with respect to the reference line. In USA and UK, the symbol is placed below the reference line for welds on the arrow side. ISO has accomodated both and designate them as A and E (for European system). The designer must be aware of these two systems and take care that his drawing is not misinterpreted.
Size of fillet Depth of
in inches preparation in inches
[/ 2 to 4
Field weld Length and pitch
points to tail in inches
Fig. 8.2 Size location, field weld length, and pitch
Fig. 8.4 Straight line always on left