The Arrow Head
The head of the arrow is used to point directly to the spot that is expected to be welded on the blueprint
. This arrow does not always have a straight section, it may be angled to pinpoint the exact location of the weld depending on geometry. Circle Injunction
The circle injunction is seen on round geometries that will require a weld all around – it can also be referred to as the 'all around weld symbol' and specifies that every possible portion of the joint needs to be welded. In some cases the weld symbol is referring to a non-circular joint, in which case the circle injunction will not be present. The Flag
The flag portion of the welding symbol is a callout to imply whether or not the weld is intended to be performed in the field. If the flag is present, the weld will occur in the field. If the flag is not present, the weld will occur in a manufacturing facility.
The flag is important to take note of as the process for welding will change dramatically based on the environment the welding will occur in. The Reference Line
The reference line contains the bulk of the information about the weld. It will provide information on things like the joint design, the weld pattern, weld size, and many other elements.
The reference line is not always double sided or single sided – it can have two different types of information on the top and bottom, which implies that the top of the joint to be welded will receive a different type of weld than the bottom side. If there is no bottom side on the reference line, then only the top side of the joint will be welded, and vice versa. Groove Design
There are various types of grooves
that can be seen on joints prepared for welding, and this aspect of the welding symbol specifies which groove weld symbol is to be expected.
The most common groove designs in industry are the fillet weld and V-Groove, but there are many other types out there like the X Groove, I-Groove, and U-Groove. The Weld Size
The weld size specifies the dimension of the actual weld itself once completed. This size effects the overall strength of the weld and can also affect how much distortion the part experiences during the welding process as a direct result of the amount of heat input.
There are two primary callouts for the weld size, S & E. S stands for size, and is most commonly seen on fillet welds. E stands for the effective throat of the weld and is most used in groove welding. The Weld Pattern
The weld pattern is not a commonly utilized part of the welding symbol as most welds are full length, but essentially what this callout specifies is the pitch (center to center distance of the welds, P), and length (actual length of each weld seam).
Weld patterns are utilized when distortion or excessive material consumption is a concern on a weldment.
The pattern below is also referred to as a stitch weld, and the weld pattern callout is also known as a stitch weld symbol.