Projection Weld Symbols: Diagrams & Guide

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When using projection welding, the spot weld symbol must be used with the projection welding process reference in the tail of the welding symbol.

The spot weld symbol must be centered on the reference line.

Embossments on the arrow side member of a joint for projection welding shall be indicated by placing the weld symbol on the side of the reference line toward the reader (fig. 3-72).

Projection Weld Symbols
Projection Weld Symbols – Fig 3-72

Embossment on the other side member of a joint for projection welding shall be indicated by placing the weld symbol on the -side of the reference line away from the reader (fig. 3-73).

other side projection weld symbol fig3 73
Other Side of Joint – Projection Weld Symbol – Fig 3-73

Proportions of projections must be shown by a detail or other suitable means.

Dimensions of projection welds must be shown on the same side of the reference line as the weld symbol.

Size of Projection Welds

Projection welds must be dimensioned by strength. Circular projection welds may be dimensioned by size.

The size of circular projection welds shall be designated as the diameter of the weld expressed in fractions or in decimals in hundredths of an inch and shall be shown, with or without inch marks, to the left of the weld symbol (fig. 3-74).

The strength of projection welds shall be designated as the minimum acceptable shear strength in pounds per weld and shall be shown to the left of the weld symbol (fig. 3-75).

Symbol for Strength of Projection Welds
Symbol for Strength of Projection Welds – Fig – 3-75

Spacing of Projection Welds

The pitch of projection welds shall be shown to the right of the weld symbol (fig. 3-76).

Projection Weld Spacing Symbols
Projection Weld Spacing Symbols – Fig. 3-76

Number of Projection Welds

When a definite number of projection welds is desired in a certain joint, the number shall be shown in parentheses (F, fig. 3-77).

Projection Weld Number Symbols
Projection Weld Number Symbols – Fig. 3-77

Extent of Projection Welding

When the projection welding extends less than the distance between abrupt changes in the direction of the welding or less than the full length of the joint, the extent shall be dimensioned (fig. 3-78).

Symbols for Extent of Projection Welds
Symbols for Extent of Projection Welds – Fig. 3-78

Flush Resistance Seam Welded Joints. When the exposed surface of one member of a resistance seam welded joint is to be flush, that surface shall be indicated by adding the flush contour symbol to the weld symbol, observing the usual location significance (fig. 3-71).

Contour of Resistance Seam Welds Symbols
Contour of Resistance Seam Welds Symbols – Fig. 3-71

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