1. Elementary SymbolsThe 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

1

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 SymbolsElementary symbols may be supplemented by a symbol characterising the shape of the external surface, or shape of the weld.

NoteThe 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

2

4. Method of RepresentationTo 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.

1 = arrow line2a = reference line (continuous line)2b = identification line (dashed line)3 = welding symbol

5. Position of continuous line & dashed lineThe dashed line can be drawn either above, or beneath, the continuous line – as shown

or

6. Relationship between the arrow line and the joint

3

1 2b

2a3

joint

Figures below show the meaning of the ‘arrow side’ of the joint and the ‘other side’ of the joint

7. Position of the arrow line

4

arrow line

‘arrow side’‘other side’

arrow line

‘other side’‘arrow side’

arrow line

‘arrow side’

‘other side’

arrow line

‘other side’

‘arrow side’

arrow linejoint A

‘arrow side’ of joint A

‘other side’ of joint A

joint B

arrow line

join

t A

‘arrow side’ of joint B

‘other side’ of joint A

join

t B

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 lineThe 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: -

NoteFor symmetrical welds, the dashed line is unnecessary - & should be omitted – as shown.

9. Specifying the Dimensions of Welds

5

To be welded on the arrow side To be welded on the other side

Weld cross-section dimensionsThese are written on the left-hand side of the symbol (before the symbol) and certain letters are used to indicate particular dimensions, namely: -

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: -

An intermittent fillet weld would be shown as follows: -

6

a

Z

ss

300Z 8

a

s

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)

10. Complementary indications

7

n x l x (e)Z

(for a fillet with a specified leg length)

n x l x (e)a

(for a fillet with a specified throat thickness)

l length of weld

( e ) distance between weld lengths

n number of weld elements

( e ) ll

n x l ( e )c

c n x l ( e )

d n ( e )

d n ( e )

NoteThe dashed line is omitted to indicate that it is a symmetrical weld (fillet size the same on arrow side & other side)

( e )

( e )

n x lZ

n x lZ

( e ) ( e )ll ( e )

l( e )( e )

ll

Peripheral weldsWhen a weld has to be made all round a part, the symbol is a circle – as shown below

Field or site weldsA flag is used to indicate a field or site weld – as shown below

Indication of the welding processIf 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 lineFurther 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

8

111

ISO 4063 gives the numbers allocated for each welding process, e.g.,MMA SAW

135 MAG141 TIG

WPS 777

Z8

8mm leg fillet weld all round