Welding References

1-3. Kinds of welding symbols

Table 1 Basic welding symbols (Excerpted from JIS Z 3021) (Refer to A2.4 for the AWSstandard)
Type of weld Basic welding
symbol
Remarks
Double−flanged ―――
Single−flanged ―――
Square groove Upset weld, flash weld, and friction weld are included.
Single−Vgroove,
Double−Vgroove
(X groove)
For an X−groove weld, draw this symbol symmetrically about the reference line for exposition (the reference line). Upset welds,flash welds, and friction welds are included.
Single−bevel groove,
Double−bevel groove
(K groove)
For a K−groove weld, draw this symbol symmetrically about the reference line. Draw the vertical line of the symbol on the left side. Upset welds, flash welds, and friction welds are included.
Single−Jgroove,
Double−Jgroove
For a double−Jgroove weld, draw this symbol symmetrically about the reference line. Draw the vertical line of the symbol on the left side.
Single−Ugroove,
Double−Ugroove
(H groove)
For an H−groove weld, draw this symbol symmetrically about the reference line.
Single−flare−Vgroove,
Double−flare−Vgroove
For a double−flare−Vgroove, draw this symbol symmetrically about the reference line.
Single−flare−bevel groove,
Double−flare−bevel groove
For a double−flare−bevel groove weld, draw this symbol symmetrically about the reference line.
Fillet weld Draw the vertical line of the symbol on the left side. For parallel welds, draw this symbol symmetrically about the reference line. For staggered welds, the symbols shown below can be used.
Plug, Slot ―――
Bead, Surfacing For surfacing, duplicate this symbol side by side.
Spot, Projection,
Seam
This symbol represents welds made by electric resistance welding, arc welding, and electron beam welding on lap joints, excluding fillet welds. For a seam weld, duplicate this symbol side by side. If possible, draw the following symbols as specified :
for a spot weld ; for a seam weld.


Table 2 Supplementary symbols
Item Supplementary
symbol
Remarks
Weld surface
shape
Flat
Convex
Concave
Draw the convex symbol outward from the
reference line.
Draw the concave symbol outward from
the reference line.
Weld finishing
method
Chipping
Grinding
Machining
Not specified
For finishing by grinding
For finishing by machining
No finishing method is specified.
Field welding
All−around peripheral welding
All−around peripheral field welding
This symbol may be omitted where all−
around peripheral welding is obvious.


(1) For welds on the opposite side or the other side of the arrow



(2) For welds on the arrow side or the near side



1-3-2. Examples of welding symbols

Weld profile Actual weld joint  Welding symbol
Field welding
The arrow side or
the near side
The opposite side or
the other side of the arrow
The arrow side or
the near side
The opposite side or
the other side of the arrow
Both sides
For a root gap of 2mm
For a root gap of 2mm
Welds with 16−mm groove
depth, 60°groove angle,
2−mm root gap, and
19−mm plate thickness
Welds with steel backing :
12−mm plate thickness,
45°groove angle, 4.8−mm
root gap, machined for
surface finishing
Partial penetration weld :
12−mm plate thickness,
5−mm groove depth,
60°groove angle,
0−mm root gap
Groove depth : 16mm on
the arrow side, and 9mm on
the opposite side ; Groove
angle : 60°on the arrow side,
90°on the opposite side ;
Root gap : 3mm
On both sides : 25−mm
groove depth, 25°groove
angle, 6−mm root radius,
0−mm root gap
T joint with steel backing :
45°groove angle,
6.4−mm root gap
Groove depth : 16mm on
the arrow side, 9mm on
the opposite side ; Groove
angle : 45°on the arrow
side, 45°on the opposite
side ; Root gap : 2mm
Fillet welds with different
leg length on both sides
Fillet welds with 6−mm leg
length on both sides
Parallel welds : 50−mm
weld length, 3 welds,
150−mm pitch

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