WELDED JOINTS - SYMBOLIC REPRESENTATION ON DRAWINGS (to BS EN 22553)
1. Elementary Symbols
The symbols shown below are some of the symbols given in the Standard
Designation
Illustration
Symbol
square butt weld
single-V butt weld
single-bevel butt weld
single-V butt weld with broad root face
single-bevel butt weld with broad root face
single-U butt weld
single-J butt weld
backing run (USA - back or backing weld)
fillet weld
plug weld (USA - slot or plug weld)
spot weld (resistance welding)
edge weld
Supplementary Notes
for Welding Inspection
1
Rev. 3
7/04
WELDED JOINTS - SYMBOLIC REPRESENTATION ON DRAWINGS (to BS EN 22553)
2. Combinations of Elementary Symbols
Elementary symbols are combined for welding from both sides – as shown below
Designation
Illustration
Symbol
double-V butt weld (X weld)
double-bevel butt weld
double-V butt weld with broad root face
double-bevel butt weld with broad root face
double-U butt weld
3. Supplementary Symbols
Elementary symbols may be supplemented by a symbol characterising the shape of the external
surface, or shape of the weld.
Note
The absence of a supplementary symbol means that the shape of the weld surface does not
need to be indicated precisely.
Shape of weld surface or weld
Symbol
flat (usually finished flush)
convex
concave
toes shall be blended smooth
permanent backing strip used
M
removable backing strip used
MR
Supplementary Notes
for Welding Inspection
2
Rev. 3
7/04
WELDED JOINTS - SYMBOLIC REPRESENTATION ON DRAWINGS (to BS EN 22553)
4. Method of Representation
To specify a weld detail it is necessary to show a weld symbol together with: 

an arrow line – completed by an arrow head
two reference lines consisting of:one continuous line
one dashed line *
(* see exception below)
The arrow line joins one end of the continuous reference line to form an angle with it.
2a
3
2b
1
1 = arrow line
2a = reference line (continuous line)
2b = identification line (dashed line)
3 = welding symbol
joint
5. Position of continuous line & dashed line
The dashed line can be drawn either above, or beneath, the continuous line – as shown
or
Supplementary Notes
for Welding Inspection
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Rev. 3
7/04
WELDED JOINTS - SYMBOLIC REPRESENTATION ON DRAWINGS (to BS EN 22553)
6. Relationship between the arrow line and the joint
Figures below show the meaning of the ‘arrow side’ of the joint and the ‘other side’ of the joint
Supplementary Notes
for Welding Inspection
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Rev. 3
7/04
WELDED JOINTS - SYMBOLIC REPRESENTATION ON DRAWINGS (to BS EN 22553)
7. Position of the arrow line
The position of the arrow line with respect to the weld is no special significance except for
single bevel or single-J welds. For these, arrow line has to point to the plate that is prepared.
This same detail can be indicated by moving the position of the dashed line (other side) – as
shown below: -
8. Position of the symbol with respect to the reference line
The symbol is placed either above or beneath the reference line as follows: 

The symbol is placed on the continuous line side of the reference line if the weld (weld face)
is on the arrow side of the joint
The symbol is placed on the dashed line side if the weld (weld face) is on the other side of
the joint
This is illustrated below: -
To be welded on the other side
To be welded on the arrow side
Note
For symmetrical welds, the dashed line is unnecessary - & should be omitted – as shown.
Supplementary Notes
for Welding Inspection
5
Rev. 3
7/04
WELDED JOINTS - SYMBOLIC REPRESENTATION ON DRAWINGS (to BS EN 22553)
9. Specifying the Dimensions of Welds
Weld cross-section dimensions
These are written on the left-hand side of the symbol (before the symbol) and certain letters are
used to indicate particular dimensions, namely: s
s
s = depth of penetration
Butt welds are to have complete penetration unless the symbol shows a penetration depth
a = throat thickness (of a fillet weld)
Z = leg length (of a fillet weld)
s
can also be used to show the depth of penetration required for a deep penetration
fillet weld: -
Weld length dimensions
These are written on the right-hand side of the symbol (after the symbol)
A 300mm long fillet weld with an 8mm leg would be shown as follows: -
Supplementary Notes
for Welding Inspection
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Rev. 3
7/04
WELDED JOINTS - SYMBOLIC REPRESENTATION ON DRAWINGS (to BS EN 22553)
An intermittent fillet weld would be shown as follows: -
A staggered intermittent fillet weld would be indicated as below: -
Other weld dimension indicators
c =
width of slot (for a plug or slot weld)
width of weld (for a resistance seam weld)
d =
diameter of hole (plug weld)
diameter of spot (spot weld)
Supplementary Notes
for Welding Inspection
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Rev. 3
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WELDED JOINTS - SYMBOLIC REPRESENTATION ON DRAWINGS (to BS EN 22553)
10. Complementary indications
Peripheral welds
When a weld has to be made all round a part, the symbol is a circle – as shown below
Field or site welds
A flag is used to indicate a field or site weld – as shown below
Indication of the welding process
If required, the welding process is shown by a number written between the two branches of an open
fork, at the end of the reference line – as shown below
Sequence of information in the tail of the reference line
Further information can be added to the open tail of the reference line but it should be added in the
following order (and each one separated by a line)




welding process (to ISO 4063)
acceptance level (to ISO 5817)
working (welding) position (to ISO 6947)
filler materials (to ISO 544, ISO 2560, ISO 3581)
In addition, a closed tail can be used which indicates a specific instruction, e.g., a procedure sheet –
as shown
Supplementary Notes
for Welding Inspection
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