What Is the Most Important Element of a Blue Print Welding

Juli 18, 2022 Posting Komentar

Whether you're an experienced welder or have considered pursuing a career in the field, you've most likely heard of welding blueprint symbols. Similar to how a web designer uses code when creating a website or a CNC machinist follows blueprints for their designs, welders often rely on welding symbols to create their welds. Welders interpret and decipher the symbols when creating their work.

If you're unfamiliar with welding symbols, don't panic! While they can look intimidating at first, learning the basics behind what they mean can transform your welds. Keep reading to learn all about what welding blueprint symbols are, the basics of how to read them and more.

What Are Welding Blueprint Symbols?

Welding blueprint symbols are used as a means of communication between a designer, such as a shop foreman, welding engineer or supervisor, and welder. Essentially, they are a set of symbols used as a shorthand code for describing the type of weld, its size and other processing and finishing information. They appear on engineering and fabrication drawings, which the welder will refer to in order to create their weld.

Welders live by the 1/16^th rule—meaning their welds can be larger or smaller than what is specified by no more than 1/16^th of an inch. Precision is key in this industry, so it's important for welders to have an understanding of blueprints and how to follow them in order to create welds that are up to standard.

Before starting their weld, welders will typically look at a Welding Procedure Specification (WPS), which is a document that gives direction to the welder by providing information such as material thickness, the general position the part needs to be welded in, the electrodes to use and more. From here, the welder will look at the welding blueprint, which contains weld symbols, specific measurements and other information needed to complete the task. These blueprints come in different forms, such as isometric, orthographic and 3D.

There are a wide variety of welding blueprint symbols that represent all different types of welds. These symbols aren't used in every industry—however, they are commonly used in industries such as construction, which require parts and pieces that meet exact specifications. Welders in these industries rely on blueprints to guide their work every day.

Understanding the Basic Structure of a Welding Symbol

According to the American Welding Society, a welding symbol consists of several elements. The skeleton of a welding symbol contains a horizontal line, called the reference line, which acts as an anchor that all of the welding symbols are tied to. The instructions for making the weld appear along this reference line. From here, an arrow connects to this horizontal line to show the joint that is to be welded.

In addition to these two elements, welding symbols may include other elements to convey specific welding information. Welding information may also be conveyed in other ways, such as by drawing notes or details, specifications, codes, standards or other drawings, which eliminates the need to include corresponding elements in the symbol.

The tail of a welding symbol is used for designating the welding, brazing and cutting process in addition to the welding or brazing specifications, procedures or supplementary information to be used in making the weld or braze. The process, identification of the filler metal to be used and other important data are placed in the tail of the symbol.

All elements have specific locations within a welding symbol, which can be seen in the image below:

elements have specific locations within a welding symbol

Image Credit: AWS A2.4

Weld symbols, which are drawn in contact with the reference line, include the following:

Weld symbols

Image Credit: AWS A2.4

Finally, supplementary symbols, which are used in connection with welding symbols, appear as the following:

supplementary weld symbols

Image Credit: AWS A2.4

Joint Types

Another important concept for welders to be familiar with is basic welding joint types, which include butt, corner, T, lap and edge joints. A joint is an edge or point where two or more plastic or metal pieces are joined together. A visual representation of each type of joint can be seen below:

basic welding joint types

Image Credit: AWS A2.4

To learn more about the structure of welding symbols, download the AWS A2.4:2007 Standard Symbols for Welding, Brazing, and Nondestructive Examination.

How to Read Welding Blueprints

In order to read welding blueprints, it's important to understand the different types of welds and their symbols. Each welding position has its own symbol, which is often placed near the center of the reference line. This symbol appears as a drawing that represents a simplified cross-section of the weld.

While there are many different types of weld symbols, here are six basic types of welds:

Fillet

The fillet weld symbol is one of the most recognized. It is used to make corner joints, lap joints and T-joints. It appears as a triangular shape, however its shape is not always an isosceles or right triangle. Formed by fitting up two members, weld metal is deposited in a corner and penetrates and fuses with the base metal to form the joint.

The fillet weld symbol