CONTOUR AND FINISH SYMBOLS

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(a) FLUSH OR FLAT COM TOUR

Supplementary contour symbols are used with the weld symbols to indicate how the face of the weld is to be finished, Figure 10.18. In addition, finish symbols may be used with contour symbols to indicate the method to be used for forming the contour of the weld. Letter designations are used for this purpose: “C” for chipping, “G” for grinding, “M” for machining, “R” for rolling, “H” for hammering, “P” for planishing, and “U” for unspecified. Applying the letter “U” to a contour symbol signifies any method of finish may be used. A standard finish mark or may be applied to the contour symbol with a numerical degree of finish shown above the finish mark, Figure 10.19.

WELD FINISHED FLUSH WITH BASE METAL

SYMBOL AS WELDED SIGNIFICANCE

(Ы ARROW SIDE, FLUSH CONTOUR SYMBOL PLASHING

FIGURE 10.18 ■ Contour symbols.

Note that contour and finish symbols are placed on the same side of the reference line as the weld symbol. They are located directly above the weld symbol when the weld symbol is on the other side of the reference line, and directly below the weld symbol when it is located on the arrow side of the reference line.

FIGURE 10.19 ■ Finish symbols.

FIGURE 10.20 ■ Application of finish symbols.

FIGURE 10.21 ■ Specifying more than one weld.

). Machinists make

chamfered

T

a clear distinction between bevel and chamfer, but weld fabricators often simply apply the term “bevel” to both. When a bevel or J-groove weld symbol (either single or double) is used, the arrow will point with a definite break toward the member to be shaped. In Figure 10.22(a) and (c), the break in the arrow indicates that the upper member of the joint is to be beveled. In Figure 10.22(b), the right-hand member of the joint is to be prepared.

DIMENSIONS ON WELDING SYMBOLS

FIGURE

10.22 ■ Designation of weld ( beveled members.

The finish symbols commonly used are shown in Figure 10.19 and Figure 10.20. However, manufactur-
ers may use their own designations for finishing. Although the degree of finish is not included in the AWS
standards, many manufacturers do indicate a desired finish,

particularly in the case of flush or flat welds. An example of
such a specification is the 250-microinch finish requirement
shown in Figure 10.19. The method of obtaining this finish
may or may not be indicated.

There are definite locations on the welding symbol for designations of the size or strength of the weld, length of the weld, pitch (center-to-center spac­ing), and the number of welds (in the case of plug, slot, spot, stud, seam, or projection welds). These locations are determined by the side of the reference line on which the weld symbol is placed, Figure 10.23(a) and (b).

MULTIPLE WELD SYMBOLS

When more than one weld is required for a joint, a symbol is shown for each weld, Figure 10.21.

DESIGNATION OF MEMBER TO BE BEVELED

Certain welds require that one of the members of the joint be beveled before the weld is actually made. To be precise, a bevel describes an edge preparation with a sharp or “feather” edge ( ), or with a

root face or “land” (

S(E)

GROOVE ANGLE; INCLUDED ANGLE OF COUNTERSINK FOR PLUG WELDS

ROOT OPENING OR DEPTH ■ OF FILLING FOR PLUG AND SLOT WELDS

DEPTH OF PREPARATION SIZE OR STRENGTH FOR CERTAIN WELDS

REFERENCE

LINE

LENGTH OF WELD

y—PITCH (CENTER-TO - / CENTER SPACING) OF WELDS

NUMBER OF SPOT, SEAM, SLOT, STUD, PLUG, OR PROJECTION WELDS

GROOVE WELD SIZE

(a) LOCATION OF DIMENSION WHEN WELD SYMBOL IS ON OTHER SIDE OF REFERENCE LINE

R A

(N)

FIGURE 10.23 ■ Location of dimensions.

(b) LOCATION OF DIMENSIONS WHEN WELD SYMBOL IS ON ARROW SIDE OF REFERENCE LINE

FIGURE 10.24 ■ Size dimensions applied to weld symbols.

The location for the number of spot or projection welds may be either above or below the symbol since there may be no arrow side or other side significance for these symbols.

Figure 10.24 shows how dimensions are applied to symbols. A detailed explanation of their application is presented in later units which refer to specific welds.

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