Machinery's Handbook, 31st Edition
1618
Welding Symbols Weld and Welding Symbols
American National Standard Weld and Welding Symbols.— Graphical symbols for welding provide a means of conveying complete welding information from the designer to the welder by means of drawings. The symbols and their method of use (examples of which are given in the table following this section) are part of the American National Stan- dard ANSI/AWS A2.4-2012 sponsored by the American Welding Society. In the Standard a distinction is made between the terms weld symbol and welding symbol . Weld symbols, shown in the table Basic Weld Symbols , are ideographs used to indicate the type of weld desired, whereas welding symbol denotes a symbol made up of as many as eight elements conveying explicit welding instructions. The eight elements which may appear in a welding symbol are: reference line; arrow; basic weld symbols; dimensions and other data; supplementary symbols; finish symbols; tail and specification; and process or other reference. The standard location of elements of a welding symbol are shown in Fig. 1.
Finishing symbol
Groove angle; included angle of countersink for plug welds Length of weld
Contour symbol
Root opening; depth of filling for plug and slot welds
Groove weld size Depth of groove
Pitch (center-to-center spacing) of welds
F A R
Size or strength for certain welds
Field weld symbol
} { } {
Arrow connecting reference line to arrow side member of joint
S or D (S)
Tail
L–P
T
(Tail omitted when reference is not used)
(N)
Specifications, process or other reference
Weld-all-around symbol Reference line Weld symbols must be contained within the length of the reference line (and not at either end)
Number of spot, seam, stud, plug, slot, or projection welds Elements in this area remain as shown when tail and arrow are reversed
Basic weld symbol or detail reference
Fig. 1. Standard Location of Elements of a Welding Symbol Reference Line: This is the basis of the welding symbol. All other elements are oriented with respect to this line. The arrow is affixed to one end and a tail, when necessary, is affixed to the other. Weld symbols should be contained within the length of this line. Arrow: This connects the reference line to one side of the joint in the case of groove, fil let, flange, and flash or upset welding symbols. This side of the joint is known as the arrow side of the joint. The opposite side is known as the other side of the joint. In the case of plug, slot, projection, and seam welding symbols, the arrow connects the reference line to the outer surface of one of the members of the joint at the center line of the weld. In this case the member to which the arrow points is the arrow side member: the other member is the other side member. In the case of bevel and J-groove weld symbols, a two-directional arrow pointing toward a member indicates that the member is to be chamfered.
Copyright 2020, Industrial Press, Inc.
ebooks.industrialpress.com
Made with FlippingBook - Share PDF online