As in any other case, Symbols are used to specify and better understand the information we want. The welding symbols are used to plot designs onto a plane and used in engineering (industries). It helps the engineer to do work in a practical and precise way, obeying specific rules.
American Welding Society (AWS) established a set of basic symbols for welding and its application in the industry. The welding symbols are used to report a series of instructions graphically.
Lengthy explanations are not needed to understand them. Necessarily, to understand and graph the plane’s designs, we need to know what types of symbols are basically used.
Application of Welding Symbols
The Reference Line. In any weld design, you start by drawing a horizontal line called the Reference Line. From this line, the other symbols will be added to complement the design.
When we proceed to do the welding, the procedures will be placed below or next to the reference line. Simultaneously, an arrow will indicate the place or “joint” where the welding will take place. The joint is the place where you proceed to weld.
An arrow indicates the two sides of a “joint.” There are some designs where we find two hands drawn. One opposite the other, depending on how you want to put together the engineering work. Each arrow represents an optimal option for welding.
Complementary welding symbols. They are those that complement the welding work. The emblem will abbreviate specific instructions that are necessary for the graphic on the plane.
The flag where it is attached to the Reference Line. A banner on the reference line indicates that the welding will be done in the field or while it is being manufactured.
The empty Circle between the reference line and the arrow. This symbol is used to indicate that welding must occur around or around the entire Circle.
The tail”. Add additional information about the plan. It is the place where communication that helps the welding job will be placed.
Welding Symbols Recommendations
- Your reference line may have different directions. When your weld symbol is below your reference line, the part to weld will be on the side of the joint where the arrow is pointing. If, on the contrary, it is above the reference line, the weld will be made on the opposite side of the joint where the arrow points.
- Graph the direction of the arrow. The arrow can indicate different directions, as we have said. The broken hand may be found, pointing you in various directions.
- Proceed to add dimensional dimensions to the right side of the symbol. The first dimension to be made will be concerning the length of the weld. The second additional dimension will show you the distance between the weld centers. There are a variety of signs to complement the design according to the need of the engineer.
Welding Symbols Precautions
- The symbols in welding simplify a series of instructions in a plane, and they would cover too much space, making heavier understanding.
- Each symbol or graphic represents a design to follow from a job to be done.
- The “tail” can be omitted when no reference line is used. It has no particular information.
Common welding symbols
1. Arrow and reference line
This is a quick way to know you see a weld symbol. The arrow points to the joint where the weld will be placed, while orientation and weld type information is given along the side of the arrow or reference line.
2. Type of welding
Along the reference line’s sides, a symbol representing the joint design or the finished weld indicates the type of weld, using commonly used groove weld symbols, including V-butt joints, joints taper, and fillet welds. Circles and spot welds indicate spot welds by a circle crossed by two parallel lines.
3. Positioning or orientation of the weld.
If the weld type symbol appears below the reference line, the weld should be on the same side of the connection as the arrow. If it is above the reference line, it is on the opposite side of the joint. If the symbol repeats both above and below the reference line, both sides of the joint should be welded.
4. Weld the outline
Whether a weld should be flush, concave, or convex is indicated by a line along the icon representing the type of weld. A straight line indicates a flush weld, and concave and convex welds are indicated by curved lines.
5. Size of the weld
The numbers on either side of the base weld symbol indicate the size. The number to the left of the weld symbol indicates the width and the number to the right indicates the length.
Sometimes there are two numbers to the right of the symbol, separated by a hyphen. When you do this, there will be multiple welds, as is the case with intermittent fillet welds, and the second number indicates the distance between the centers of each individual weld.
For a fillet weld, if the fillet symbol is displayed both above and below the reference line with the same number to the left at each point, the welder should create an equilateral weld.
6. Additional symbols
One of the most important additional pieces of information from an entrepreneur’s perspective is a small flag along the reference line. This indicates that the weld is an on-site weld (i.e. a weld that must be done on-site).
More details on the type of welding or how it is performed can be found at the end of the arrow. (If no additional information needs to be provided to the welder, the glue is usually left out.)
Often, this additional information is in the form of an abbreviation, which in the United States is based on reference codes from the American Welding Society and indicates a specific welding process. For example, FCAW stands for Flux-Cored Arc Welding, while SMAW stands for Shielded Metal Arc Welding (both of which are commonly used in construction).
Although they are less likely to be encountered in the United States, you can also find numbers at the end of the lean. In this case, the ISO codes of the International Organization for Standardization (136 corresponds to FCAW; 111 corresponds to SMAW).