If no length is given, then the weld is to be placed between specified dimension lines (if given) or between those points where an abrupt change in the weld direction would occur (like at the end of the plates in the example above). The Length & Pitch of Intermittent Welds:
An intermittent weld is one that is not continuous across the joint, but rather is a given length of weld separated by a given space between them. This method of welding may be used to control heat distortion or where the joint strength requirements allow. Intermittent welding can save time and money if a long weld is not necessary. Used more frequently than the length alone, the length and pitch (length first, spacing second) are two numbers located at the right of the fillet weld symbol.
The length appears first as before followed by a hyphen then the pitch is shown. The pitch refers to a dimension from the center of one weld to the center of the next weld.
The pitch is not the space between welds but a measurement from center to center of the welds. To get the spacing for layout subtract the length of one weld from the pitch.
The intermittent welds may be chain intermittent or staggered intermittent. Chain
intermittent the welds on both sides of the joint are opposite each other and resemble a chain. Staggered intermittent the welds on the opposite side are usually started in the gap between the welds on the first side. The welds then appear staggered. If the welds are staggered the fillet weld symbol will be staggered on the reference line.
Contours:
Some welding symbols may show a contour finish that details how the fillet weld shape must be finished after welding. The contour may be flat or convex (having a surface that is curved or rounded outward) and the element to describe this is placed above the slope on the fillet weld symbol. A letter to indicate the method of finish may be given above the finish element.
Groove Welds:
The groove weld is commonly used to make edge-to-edge joints, although it is also often used in corner joints, T joints, and joints between curved and flat pieces. As suggested by the variety of groove weld symbols, there are many ways to make a groove weld, the differences depending primarily on the geometry of the parts to be joined and the preparation of their edges. Weld metal is deposited within the groove and penetrates and fuses with the base metal to form the joint. (Note: for the sake of graphical clarity, the drawings below generally do not show the penetration of the weld metal. Recognize, however, that the degree of penetration is important in determining the quality of the weld.
Groove Weld Size - The groove weld size is given in two dimensions and like the fillet weld it is placed to the left of the weld symbol. The first size given is the depth of the groove and is the dimension used to prepare the edge preparation. The depth of groove is measured from the surface of the joint to the bottom of the preparation.
The depth of groove does not include weld reinforcement or root penetration. The second size given is the actual weld size and is enclosed in parentheses to distinguish it from the groove size, or depth of groove.
The actual weld size is again measured from the surface of the groove through the bottom of the groove but now includes the expected penetration of the weld. On a square groove only the weld size is given.
The weld size does not include face reinforcement or root reinforcement.
Groove Opening & Angle - Two other important elements for preparing and welding the groove are the root opening and the groove angle. The root opening, when used, dimensions the space between the joint to be welded and is placed inside the weld symbol. The groove angle is also placed inside the weld symbol and is given in degrees.
The groove angle for a V groove is given as the included angle so that means the edge bevel or chamfer for each piece is 1/2 of the degrees given.
For example; A 45 degree included angle means bevel each member at 22 1/2 degrees. J grooves angles may be detailed elsewhere on the drawing. The root
opening and groove angle are separate elements and may or may not appear together depending on the joint requirements.
On some drawings the root opening or groove angle will be covered in a note or
specification on the drawing for all similar symbols, and does not appear on the symbol. The Welder must always read all information given on a drawing.
Contour & Finishing - The same contour symbols that apply to fillet welds may be used with groove welding and are placed above the weld symbol.
Square Groove - The square groove weld, in which the \tight fit or a slight separation of the edges. The amount of separation, if any, is given on the weld symbol.
V-Groove - The V-groove weld, in which the edges of both pieces are chamfered, either singly or doubly, to create the groove. The angle of the V is given on the weld symbol, as is the separation at the root (if any).
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