204 Welding Print Reading the weld into the joint and provides clearance for the electrode. Burning, grinding, arc gouging, chiseling, or machining removes the metal. Root Opening, Groove Angle, and Bevel Angle It is important to be familiar with the common terms associated with groove joints and the preparation of groove welds. The root opening is the gap at the joint root workpieces, Figure 16-2. The joint root refers to the part of a joint to be welded where the members align closest to each other. The root opening is used to provide access to the joint for the electrode and improved weld penetration. When additional clearance or penetration is needed for thicker material, an angle is placed on the edge of the material. A groove angle is the total angle formed between the groove face on one workpiece and the groove face on the other workpiece. The groove face is the joint member surface included in the groove. A bevel angle is the angle formed between the bevel of one piece and a plane perpen- dicular to the surface of the piece. The angle may be placed on one side of the joint, as with a single-bevel- groove, or the angle may be placed on both sides, as in a V-groove. A V-groove weld applied to the joint in Figure 16-2 is shown in Figure 16-3. Also shown is the welding symbol. Note that the distance specified for the root opening (.06) is shown inside the groove weld symbol and the groove angle information (60°) is placed outside the weld symbol. As with fillet welds, dimensions for groove welds are shown on the same side of the refer- ence line as the weld symbol. Preparation Size and Effective Throat of Groove Welds The effective throat is the minimum distance (minus any convexity) between the weld root and the face of the weld. It describes the weld size (penetration), Figure 16-4. When specified for a weld, the effective throat is shown in parentheses to the left of the weld symbol. As shown in Figure 16-4, it appears to the right of the depth of bevel. The depth of bevel indicates the depth of preparation for preparing the joint. The effective throat of a groove weld is specified when the weld extends only partially through the members being joined. Complete joint penetration is indicated when no dimension is given on the welding symbol for a single-groove or a symmetrical double- groove weld. Figure 16-5 illustrates complete weld penetration for a double-groove joint. Figure 16-2. Common terms describing the parts of a groove joint. Groove face Root opening Bevel angle Groove angle Root face Figure 16-3. A V-groove weld with its parts identified. The welding symbol shows the root opening size and the groove angle. .06 60° Face Toe Root Reinforcement Figure 16-4. A dimension in parentheses to the left of the weld symbol gives the effective throat (weld size) of the groove weld when the weld extends partly through the members being joined. 3 4 ( ) 15 16 3 4 15 16 Desired weld Symbol Effective throat Depth of bevel Weld size (effective throat) Figure 16-5. When no dimension is given on the welding symbol, the weld should completely penetrate the joint. 3 4 3 4 121 Symbol Desired weld