Page 25 - Quick Guide to Welding and Weld Inspection by S.E. Hughes, Clifford Matthews

A Quick Guide to Welding and Weld Inspection

represents. Depending on the standard used, it is normally
positioned below or above the reference line to specify
whether the weld is on the ‘arrow side’ or ‘other side’
respectively. In BS 499 and AWS A2.4 the symbol is placed
below the reference line to represent the fact that the weld is
made from the arrow side (i.e. the side that the arrow is
touching). If the symbol is on top of the line it indicates that
the weld will be made from the opposite side (i.e. the other
side) to which the arrow is pointing (or touching). This often
causes confusion and can lead to welds being put in the
wrong position.
To avoid this confusion the ‘other side’ is represented by a
separate dashed line in BSEN 22553 (see Fig. 1.8). It
therefore does not matter if the symbol is above or below
the solid line because it will always be on the arrow side
except when placed on the dashed line. A symmetrical joint
such as a double V, which is the exact same size on both
sides, does not require a dashed line to represent the other
side because both sides are the same.
Supplementary symbols may be used to complete a joint
symbol with additional information such as a flat, concave or
convex finish (Fig. 1.9). The absence of a supplementary
symbol indicates that the weld is left in the ‘as-welded’
condition with no precise weld surface finish required.
Dimensions
Dimensions that relate to the joint cross-section, such as weld
depth or fillet sizing, are positioned on the left of the symbol.
If no weld depth is specified before the symbol on a butt weld
it is assumed to be a full penetration weld. Fillet welds will
always have a dimension relating to the leg length and/or
throat dimension. Longitudinal dimensions such as weld
lengths are positioned on the right of the symbols in most
standards (see Fig. 1.10). If no longitudinal dimensions are
specified after the symbol then the weld extends the full
length of the joint.

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Woodhead Publishing Ltd – A Quick Guide to Welding and Weld Inspection
Data Standards Ltd, Frome, Somerset – 17/9/200901QG Welding chap1.3d Page 10 of 16