Civil Engineering Reference
In-Depth Information
Deep penetration welds
The ISO standard can specify deep penetration welds, the effective
weld throat being indicated by the letter s placed in front of the
throat thickness dimension, as shown in
Fig. 10.4
. This is followed
by the nominal throat thickness preceded by the letter a. The reason
for including the nominal throat dimension is not clear because any
calculations of weld strength would be based on the 's' dimension
which is the actual throat thickness.
Illustration
ISO
S
a
S8a6
6
8
10.4
Deep penetration weld with ISO weld symbol (dimensions are in
millimetres).
Deep penetration of a weld can be achieved by high-current sub-
merged arc welding (SAW) or gas shielded metal arc welding
(GMAW) and by certain types of electrodes. The depth of penetra-
tion must be predetermined by welding procedure testing before the
dimension is used for design purposes and is included in the
welding symbol.
In the AWS standard deep penetration fillet welds are not men-
tioned as such and it is not clear how such a weld would be sym-
bolised. The dimensions of the weld would have to be specified on
a drawing note and, as mentioned above, procedure testing would
be necessary before the weld size was used in design calculations.
Double fillet welds
In a double fillet weld the dimensions are repeated even if they are
identical (see
Fig. 10.5
).
Illustration
ISO
AWS
z6
z6
66
6
6
10.5
Double fillet weld. ISO dimensions are in millimetres; AWS dimensions
are in inches.
