INTRODUCTION TO METRICS The primary system of measurement used by most of the world is the metric system. The word “metric” is derived from the Greek word “metron,” meaning measure. This system is often identified by the initials SI, which is the abbreviation for Systems Internationale. STRUCTURE OF THE METRIC SYSTEM Quantity Represented Name Symbol […]

Stud welding can be described as the joining of a metal stud to another metal workpiece by means of arc, resistance, friction, or other appropriate welding process. The stud-weld symbol is always shown placed below the reference line, Figure 21.1, with the arrow of the welding symbol pointing to the surface to which the stud […]

For multiple-joint seam welds, where one or more pieces are inserted between the two outer members, the same symbol and elements are applied to specify the weld as are used for the two-member joints, regardless of the number of pieces inserted, Figure 20.12. In such cases, the symbol has an arrow side or other side […]

A seam weld is a continuous weld made on or between overlapping members of a joint. It is a continuous weld that may consist of a single weld or a series of overlapping spot welds. The seam-weld symbol, =©= may have an arrow side or other side significance, Figure 20.1(a) and (b). Because of the […]

A projection weld is a resistance type weld that is generally applied to a lap or edge joint. The welds to be made are localized at predetermined points and appear as projections or embossments, Figure 19.1. One of the members of the lapped joint is always prepared with an embossed (raised) surface for a projection […]

The flat or flush-contour symbol and method of finish may be added to the spot-weld symbol when the exposed surface of either member of the spot-welded joint is to be made flush or flat, Figure 18.12 and Figure 18.13. Note that a machine finish may be specified as flat without a need for it to […]

OTHER SIDE IE —©—————- <(R! A spot weld is made between or on overlapping members of a joint. In cross section, the spot weld appears to be circular. The symbol for a spot weld is О. This symbol is similar to the weld-all-around symbol except that it is centered on the reference line. (Note that […]

FIGURE 17.1 ■ Typical joints to which the edge weld symbol is applied. The edge weld symbol __ has replaced the flange butt JL and corner flange L weld symbols, which have become obsolete. These former weld symbols are identified as joints to which the edge weld symbol is applied, Figure 17.1(a) and (b). Note […]

FIGURE 16.1 ■ Symbol for a built-up surface. A surfacing weld is used to build up a surface to (1) correct the size of a part, (2) provide a transition between dissimilar metals, (3) pro­vide a corrosion resistant surface, or (4) pro­vide a wear-resistant surface, and (5) reduce excessive root openings. Surfacing welds can be […]

Two or more members may be welded to another member by means of a plug weld. When this is specified, the joint or joints to be welded are shown by a section drawing. The section drawing shows the member or members that will require joint preparation, Figure 15.14(a) and (b). Note the variation on the […]