>Welding Symbols - The Basics <

ISO standards are internationally agreed by experts. Think of them as a formula that describes the best way of doing something. It could be about making a product, managing a process, delivering a service or supplying materials – standards cover a huge range of activities. Standards The British Standard for weld symbols is BS EN 22553. Identification of the weld process is required as part of the weld symbol the relevant weld process code is listed in BS EN ISO 4063.

BY ROSEMARY REGELLO

Note: If you're looking for the chart featured in Google Images, scroll down below the welding school ad on the right side.

Like other aspects of drafting, there’s a set of symbols for welding to simplify the communication between designer and builder (i.e. the welder). This language may seem a little strange at first, so it's best to learn it one symbol at a time. For example, check out the horizontal stick figures below:

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These figures represent the core structure of every drafting specification for a weld to be performed. The welding symbol has an arrow, which points to the location on the drawing where a weld is required. The arrow is attached to a leader line that intersects with a horizontal reference line. Finally, there's a tail at the opposite end of the reference line that forks off in two directions. The tail is optional and needed only for special instructions.

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Dangling from the middle of the reference line, you'll see a geometric shape or two parallel lines identifying what type of weld should be performed on the metal. This is called the weld symbol (not to be confused with the overall welding symbol ). The three weld symbols you see in the drawings above represent a square, fillet and V-groove weld, respectively.

The weld symbol may also be placed above the reference line, rather than below it. This placement is important. When the weld symbol hangs below the reference line, it indicates that the weld must be performed on the 'arrow side' of the joint. For example, In the next drawing a fillet weld is specified on the arrow side. You can see the actual weld in the second depiction.

Now, if the weld symbol appears on top of the reference line, then the weld should be made on the opposite side of the joint where the arrow points. Here's how that will look:

If the weld symbol appears on both sides of the reference line, as shown below, it specifies that a weld must be performed on both sides of the joint.

Numerous weld symbols have been devised to represent all the different weld types used in the trade, as well as any joints that must be cut or beveled during fit-up. Here are the most common ones to learn:

If you're not familiar with either welds or joints, be sure to check out those topics in the green menu box located on the top right side of this page. Even if you are familiar, it still takes time to memorize all these symbols and what type of welds they represent. Therefore, it's a good idea to print out or photocopy a chart that contains both the symbols and drawings of the completed welds. Click here to download a sample chart or look below right of this column.

Dimensions and Angles

Needless to say, numbers are also a big part of a welding specification. The width, depth, root opening and length of a weld, as as well as the angle of any beveling required on the base metal before welding can all be communicated succintly above or below the reference line.

In most cases, the weld width (or diameter) is located to the left of the weld symbol (expressed here in inches), while its length is written to the right . (As explained in Anatomy of a Weld, the weld's width is the distance from one leg of the weld to the other.) Often, no length is indicated, which means the weld should be laid down from the beginning to the end of the joint, or where there's an abrupt change in the joint on the base metal.

Dimensions written below the reference line, of course, apply to the joint on the arrow side, while dimensions written above apply to the joint on the other side. In the image above, welds are indicated for both sides of the joint.

https://everexotic.amebaownd.com/posts/15776723. Sometimes, a series of separate welds is specified, rather than a single long weld. This is common when thin or heat-sensitive metals are welded on, or where the joint is a really long one. In the following symbol and drawing, 3-inch intermittent fillet welds are specified:

Notice that the weld symbols on either side of the reference line above are offset, rather than mirroring each other. This means the welds should be located at staggered spots on either side of the joint, as shown in the drawing on the right.

A weld symbol may also specify an angle, root opening or root face dimension. This is common when the base metal to be welded on

Iso Standards Welding Symbols