Weld symbols are often used among welders and engineers. Learn how to read common welding symbols and their meaning. Common weld symbols and their meanings When welds are specified on engineering and fabrication drawings, a cryptic set of symbols is used as a sort of shorthand for describing the type of weld, its size and other processing and finishing information. Here we will introduce you to the common symbols and their meaning.
All the other elements that describe the weld are on or located around this line. The reference line has a leader and arrow that points to where the information applies. It may also have a tail that has information about the process, specification, or other notes that do not normally have an element that describes them. If the elements on the reference line describe the necessary details as it does in most cases the tail is not used. In the examples one of the reference lines has multiple arrows that are used to show the same weld in three locations that are relatively close to each other.
As its symbol suggests, the fillet weld is roughly triangular in cross-section, although its shape is not always a right triangle or an isosceles triangle. Weld metal is deposited in a corner formed by the fit-up of the two members and penetrates and fuses with the base metal to form the joint. Recognize, however, that the degree of penetration is important in determining the quality of the weld. The perpendicular leg of the triangle is always drawn on the left side of the symbol, regardless of the orientation of the weld itself. The leg size is written to the left of the weld symbol.
Resembling some sort of hieroglyphics or old English runes, cryptic welding symbols would confuse any layperson looking at a drawing or blueprint. But no welder could do his job without knowing, at the very least, what the most common and important symbols indicate. Engineering and fabrication drawings feature welding symbols that describe the type of weld, its size and other pertinent information. The need for consistency in welding led to the development of a system for indicating welding requirements.