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 applied to a flat or contoured surface and are shown on the lower side of the reference line. Because this symbol does not refer to a joint, it has no arrow side or other side signifi­cance, Figure 16.1.

FIGURE 16.2 ■ Symbol indicating full surface buildup.

When the entire surface is to be built up, whether it be the entire area of a plane or curved surface, only one element may be added to the surface symbol. This element is the minimum thickness of the buildup of the weld deposit, which is shown to the left of the symbol, Figure 16.1. When a specific height is not desired, a dimension is not given.

However, a reference in the tail of the welding symbol may be included to indicate a buildup in accordance with company standards.

For a completely built-up surface, the weld symbol may appear on a print as in Figure 16.2.

When only a portion of the surface must be built up, whether it be the area of a plane or curved surface, the extent, loca­tion, and orientation of the area to be built up is shown on the print in addition to the symbol, Figure 16.3(a). The direction of welding may also be indicated by a note in the tail of the welding symbol, Figure 16.3(b) and (c).

In cases where a surfacing weld is to be performed over another weld, a welding symbol with a multiple reference line may be used. For example, a fillet or groove weld may be the first operation, followed by the surfacing weld, Figure 16.4.

Differences in the direction of multiple surface welds may be indicated by the use of appropriate notes in the tail of the welding symbol, Figure 16.5(a).

Also, special applications of surface welds may be indicated by a note in the tail of the welding symbol, such as adjusting the fit-up of grooved joints, Figure 16.5(b).

SIGNIFICANCE REQUIRED

SYMBOL

1ST WELD

FRONT VIEW

RIGHT SIDE VIEW

SYMBOL

(b)

FILLET (FIRST WELD) SIGNIFICANCE

(a)

DIRECTION

SYMBOL

SURFACE WELDS PERFORMED AS SECOND OPERATION

GROOVE WELD PERFORMED FIRST

SIGNIFICANCE

FIGURE 16.4 ■ Applications of surface weld symbol with other weld symbols using a multiple reference line welding symbol.

SYMBOL

SIGNIFICANCE

FIGURE 16.3 ■ Length, width, and direction of surface built up by welding.

FRONT VIEW

FIGURE 16.5(b) ■ Application of surface weld for reducing root opening of a bevel groove joint.

FIGURE 16.5(a) ■ Multiple-layer (longitudinal and lateral) surface welds.

Graph paper is provided at the end of this review for your use.

1. a. Complete the following welding symbol to indicate the building up of a surface.

5. Explain the significance of the following welding symbols.

* WELD

/ LONGITUDINAL NV

WELD

/ LATERAL Nil

b. Apply and identify an element used with this symbol.

CIRCUMFERENTIAL WELD

c. On which side of the reference line is the weld symbol placed?

2. a. Does this symbol have an arrow side, other side significance?

b. Give the reason for your answer.

c.

AXIAL WELD

3. a. Show how the extent of the surfacing weld is indicated between the vertical centerlines in the following illustration.

b. Show how a 1/2" weld width is indicated with a /2" surface buildup.

6. Draw the symbol for the following. Use a suitable sketch for applying the symbol.

a.

4. a. Illustrate an axial weld direction on the following sketch of a round rod to a surface buildup.

b. Draw the welding symbol to specify this.

7. Illustrated is a hub cap punch prepared for welding and in finished form. The operation is to be done by building up with a surface weld to the desired height and machining the contour to match the 4" diameter. Allow %" for finishing the welded surface. The surface is to be welded circumferentially. Make a two-view working sketch including dimensions and necessary welding symbols to specify the required work.

8. a. Interpret the note specifying reamed holes.

b. What is the spacing of the hole in degrees?

9. a. Draw a welding symbol that specifies a circumferential surface weld with no buildup size requirement.

b. Prepare a sketch that illustrates how the weld would appear.