Like in all domains that require precision of execution, welding makes use of conventional standard signs that help to the better execution of a weld according to blueprints. The welding symbols systematized by the American Welding Society indicate the exact place where welds need to be made, the kind of joint necessary for it and the amount of filler to be used in the joint. Learning how to work with welding symbols is part of the training programs welders have to attend before receiving any certifications. What do welding symbols actually consist of? The main basic elements are the arrow, the reference line and the tail.
All welding symbols are built starting from the reference line, this is the very foundation of the sign as such on which you add other data necessary for the process. The connection between the reference line and the joint area is made by the arrow, but the direction of the arrow has no influence on the meaning of the reference line. Last but not least, the tail is not a compulsive element of all welding symbols, some have it, others don’t. It is generally used in case you want to add some information or supplementary specification to the process.
There are all sorts of peculiarities connected to the use of welding symbols. For instance, if any signs are included in the lower part of the reference line, you’ll have to make the weld on the side of the joint indicated by the tip of the arrow. In case the welding symbols are present on the upper side of the reference line, then the weld needs to be made on the side opposite to the direction pointed by the tip of the arrow. Both sides of the joint must be welded when you have signs included on both sides of the reference line. Deciphering such instructions from blueprints is essential for the proper working of the welding process.
Two kinds of welding symbols may appear on the reference line and they are essential when it comes to understanding how to make a specific weld. The most important sign here is a circle that means “welding all around”, thus, you will have to make the weld all around the joint in the direction indicated by the tip of the arrow. Sometimes it is not possible to weld around one single surface, and in such cases, the presence of the circle would be incorrect. Under such circumstances there should be other specificities related to the process.