WELDING THEORY - OD1650 - LESSON 1/TASK 1
(4) Number of Projection Welds. When a definite number of projection welds is desired
in a certain joint, the number will be shown in parentheses (figure 16, view F, on the previous
(5) 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 will be dimensioned (figure 16, view G).
(6) Flush Projection Welded Joints. When the exposed surface of one member of a
projection welded joint is to be made flush, that surface will be indicated by adding the flush
contour symbol (refer to figure 3, view C, on page 9) to the weld symbol, observing the usual
location significance (figure 16, view H).
Resistance Seam Welds.
(a) Resistance seam weld symbols have no arrow or other side significance in
themselves, although supplementary symbols used in conjunction with them may have such
significance. Resistance seam weld symbols will be centered on the reference line.
(b) Dimensions of resistance seam welds may be shown on either side of the
(2) Size of Resistance Seam Welds. Resistance seam welds will be dimensioned by either
size or strength as follows:
(a) The size of the resistance seam welds will be designated as the width of the weld,
expressed in fraction, or decimally in hundredths of an inch, and shall be shown with or without
inch marks to the left of the weld symbol (figure 17, view A, on the following page).
(b) The strength of resistance seam welds will be designated as the minimum
acceptable shear strength in pounds per linear inch, and will be shown to the left of the weld
symbol (figure 17, view B).