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An Ultimate Guide on How to Read Welding Blueprints and Symbols?

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The welding industry is regarded as one of the most revenue-generating industries in almost every part of the world. The demand for welders is increasing in the automobile, aviation, and construction industry immensely.

 People rely on welders for building gates, garden fences, and swings or to design their kitchen appliances and vehicles. The welding profession is worth adopting as research reveals that the welders themselves make around 70% of all the manufactured products.

On one side, we see how well this industry is doing, but, at the same time, the alarming thing is the stats by the American Welding Society. This society fears that by 2025 there’ll be an extreme shortage of welding professionals. You might be wondering why this is so? Well! A simple answer to this question is that they don’t know how to read welding blueprints and symbols.

I know most of you think that it’s not that important but, to be a professional welder, it is essential and mandatory to know all about welding blueprints symbols. Like a pharmacist possessing keen knowledge about all the drugs and chemicals used to make a medicine, a welder must know about the welding blueprints and symbols.

Where the Problem Arises?

Welding blueprints and symbols allow welders to produce quality work quickly and increase their market worth as they can complete their tasks correctly and in the given time. Studies suggest that the welding industry and economy go hand in hand; thus, welders are in high demand and must be educated about their profession.

The fundamental and most significant problem faced by welders is that they don’t know how to read the welding blueprints and symbols, which is the most crucial part of their work. Welding manufacturers don’t have any trainer at their workshop to educate and train them on reading welding blueprints and symbols.

It is most common in startups and small and medium-sized companies. Such companies work at economical rates and hire welders with not much experience. An inexperienced person would face difficulty, which will ultimately affect his career progress.

However, an inexperienced welder can definitely acquire such skills from some professional welding trainers. Usually, welding manufacturers, vendors, equipment distributors have this knowledge.

If you’re new in this field who find it difficult to read the blueprints, you can ask them to help you free of cost. Well! If you don’t see anyone capable enough, then bear with me. Welding blueprints might look scary and intimidating at first, but you can learn to read and understand them if you have the necessary knowledge. In this post, I’ll share an ultimate guide on how to read welding blueprints and symbols. But, before we get into the main topic let’s first discuss

  • What are blueprints, and how are they formed?
  • What are welding blueprints and symbols?
  • Why welding blueprints and symbols matters?
  • Does blueprint designs vary in size?

 So, stick with me here and read on.

What Are Blueprints and How They Are Formed?

It is essential and an excellent initiative to have information related to the things you are doing. When you heard the word Blueprints so, what the first question that might hit on every welder’s mind is that what is a blueprint?

Blueprints were first used back in the early 19th century. The prime goal of creating these prints was to represent technical diagrams and designs by associating printing mechanisms on light-sensitive paper. These designs allow the accurate and quick representation of diagrams, mainly in the manufacturing industry. As the name suggests, blueprints are like the negative of the photographs taken by the traditional camera printed as white lines on a blue background paper.

The blueprints are developed by following a chemical process known as cyanotype. This process’s end product is a blue color paper on which designs are made with white lines. The process begins by using a sheet of two types of chemical compounds: ammonium ferric citrate and potassium ferricyanide.

Wondering what happens next?

The sheet is later soaked with light-sensitive iron salt solution and left until it becomes dry. As the sheet is left in the sunlight for drying, here a photoreaction takes place. In this process, the sun rays produce a solution of potassium ferricyanide. It gives rise to insoluble blue color substance, and the remaining chemicals are drained off.

Read our How to Weld with a Butane Torch review

What Are Welding Blueprints Symbols?

In the welding industry, welding blueprints symbols are the drawings and designs that refer to any construction plan. It can be related to any building and construction work and defines step by step detailed planning.

They are used as a channel of communication among a welder, engineer, or an administrator. They guide them on how to perform their work efficiently without any further extensions. These are the code languages that describe what type of welding is required, its size, length of the weld, dimension, things needed for processing, and other relevant finishing information. The welder refers to these shorthand symbols to make their weld accurately.

Welding blueprints are commonly known as welding drawings. These two-dimensional diagrams consist of all the details that are essential for the completion of a project. Sometimes all these details are needed for taking permissions, which are ultimately linked with the welding schedule.

Every welder must know how to read the welding blueprints and symbols. If anyone tries to omit this step, then they’ll suffer badly. Hence, every welder should learn to read and understand the plans and symbols before starting the fieldwork.

Why Welding Blueprints and Symbols Matters?

Before we provide you all the tips and tricks on reading the blueprints, let’s first briefly discuss their importance. Usually, welding blueprints and symbols not given the importance they deserve. These are the technical drawings and symbols that play a critical role in project documentation and practical implementation.

 The prints are designed for project specifications. It gives off an idea of what the project is all about, how you should proceed in the project, the requirements, and most importantly, they communicate with you and have all the technical details that guide you in every stage.

Welding blueprints forms a crucial part of every project stage because the diagrams decide the basis on which the number of project phases can be finalized. For example, designs can tell about the overall cost in terms of material needed and the workforce.

The following mentioned below are some other ways that shed light on the importance of blueprints and symbols.

  • Welding blueprints and symbols allow you to measure the compliance needed against the given specification.
  • These are excellent sources for carrying the work in the correct order if any confusion or troubleshooting occurs.
  • These drawings and symbols permit you to track any addition or changes with what you’re working on.
  • They are like a road map which tells you what you have to do next.
  • Blueprints and symbols ensure that each phase of the welding project progresses smoothly to prevent rework, over budgeting, and project delays.

Welding Blueprints and Digital Technology

Digital technology has progressed significantly in the past few years and has introduced digital blueprints in the market. According to some experts, these are of great use and thus are gaining appreciation from the professionals.

There are two reasons for the popularity of digital blueprints. Firstly, they encourage welders both on the field and in the office to stay open for any modifications. Secondly, it allows them to immediately communicate with the on-field worker to work as per the new plan with just a button click.

The manufacturing industry wholeheartedly accepts this innovation. It has taken off the burden from the entire project team’s shoulders. Welders think that digital blueprints and symbols have made their work much more manageable because now chances of errors and misunderstandings can be minimized. Also, the total time to finish a task decreases dramatically.

No matter if you use blueprints on a paper or have it in digital form, it is essential and mandatory that you possess all the knowledge required to read and understand them. If not, you’ll fail as a team for sure and won’t complete your tasks. Being a welder, you might not just cause you to lose your job but also impact your company’s reputation in the market and in front of your clients. Therefore, every welder should know how to read welding blueprints and symbols.

Do Blueprint and Symbols Vary In Size?

As you know now how blueprints are developed and what are welding designs and symbols. You must be thinking that if all the plans are the same or they differ? Well! A simple answer to your query is yes.

Blueprints and symbols differ in shapes and sizes. There is a wide range of welding blueprints and symbols available, and not all logos may be used in every industry. However, when it comes to the construction industry, that includes a lot of the welding work, so here these blueprints and symbols are used extensively. Thus, at least you must know how to read the fundamental diagrams and symbols, if not the advanced ones. Welders significantly rely on these blueprints to perform their everyday work.

Welding blueprints and symbols vary from project to project. Sometimes they can be more significant, and others can be of small size; it all depends on the project specification. The traditional paper-based blueprints are of vast size whereas, the size of the digital design can be adjusted accordingly. But, as a whole, the size varies.

How to Read Welding Blueprints and Symbols?

The first and foremost important thing every welder should do before reading the blueprints is to skim and scan the entire design and give a thorough reading to all the instructions and notes included. After having a clear idea about the plan, one can focus on the specifications required to be well aware of the whole scenario.

Here don’t get confused with the plan view. It is just the first look that you’ll get once you view the design’s horizontal plane. It can be anything related to the construction industry like the garden or main gate of a house, kitchen appliances, building floors, roof plan design, plumbing plan, etc.

Each drawing puts its prime focus on the particular item included in their work and is all drawn to some specific scale. Professional welders need each symbol and later connect one with the other to form a link during the welding process.

No doubt, a welding symbol is a code, but it isn’t a single code. It comprises several different elements, which gives them a complete look.

In the next section of the guide, we are going to discuss some of the elements of welding blueprints and symbols.

Reference Line

According to the American Welding Society, the welding symbol’s frame consists of a straight flat line known as the reference line. This reference line is like an anchor to all other welding symbols present in the blueprint. All the instructions included in the plan arise with this reference line.


It is yet another important element of the welding blueprint. An arrow joins this line (like the head to tail vector) to indicate the link needing welding. The tail of the symbol is mainly designed to fix the welding. It is helpful during the cutting process stage as all the supplementary information like what metals are needed and how much quantity appears in the tail of the welding symbol.

welding Arrow

Besides a reference line and an arrow, the symbols also comprise some other elements that help communicate with the welder. Some other way by which the welding information can be imparted includes diagram codes and details. These specifications reduce the need to have any further elements in the symbols.

welding Arrow symbols

Angles and Dimensions

Angles and dimensions of the welding symbols hold an essential position in making understanding the blueprints. The blueprints are a collection of packed information that is useful to the workers. They reveal the length, depth, and width of the weld and thus constitute a significant part of the welding blueprints. To understand the welding blueprints, notice that the welding length is located at the right while the welding diameter is present towards the symbol’s left.

Weld diameter is the actual distance from one corner of the weld to the other. If the length is present, it’s okay, but if not, then it means that the weld needs to be placed from the start to the end of the weld joint.

Dimensions can be written on either above the reference line or below it. If written above, it applies to the other side of the joint and, if written below so, on the weld joint’s arrow side. If you’re using heat-sensitive metals that are thin, they come in a series rather than a single weld.

The welding symbols on any side of the reference line cancel each other instead of facing each other. It means the weld must be placed in a spread out way on both sides of the weld. As a whole, both angle and dimension give information about the length, size, and width of the metal needed to be weld.

Unique Letters on the Welding Blueprints

 When you read the blueprints, you come across several different types of letters on it. These are not just the design but have a special meaning within it.

They communicate a particular type of information while carrying on with your work, such as the start plus endpoints, how much length of the weld must be used, and its root opening. These letters are found around the symbols in the design plan. Some of the most widely used letters, along with their meanings, are as follows:

  • A: Angle of the countersink
  • C: Chipping the finish
  • F: Symbol of completion
  • G: Grinding finish
  • L: Metal or weld length
  • M: Machining finish
  • N: Total number of projection weld
  •  P: Welding pitch
  • R: Filling depth, Rolling
  • S: Depth of strength
  • T: Process specification.
  • U: Any other appropriate method might be used


Common Welding Symbols Along With Their Meanings

By now, I am sure you have acquired some fundamental knowledge of reading the welding blueprints and symbols. Let’s add more essential things in it that will make you a pro in reading blueprints and symbols. Like common letters, there are commonly used welding blueprints symbols as well. Although these are universal symbols, they are in bulk quantity.

Welders use these symbols to identify different forms of weld to complete their projects. These symbols are of great significance as they help the welder understand the weld’s size and other processing information.

There are three main types of welding symbols, namely.

  • Fillet Welds
  •  Groove Welds
  • Plug and Slot Welds
main types of welding symbols

Are you confused about their roles and meaning? Well! Don’t panic. Now, in the next section, we are going to discuss each of them separately.

Fillet Welds

Fillet Welds

This type of weld is triangular from the cross-section side and is used while making 90-degree corner joints, lap joints, and T-joints. Because of the variation in, it doesn’t need to make a ninety-degree right angle triangle. A small amount of welding metal is placed at the joint’s corners to join the two joints. It slips into the material to form a fixed joint.

Groove Weld

Groove Weld

 The groove welds are used to connect joints linked with the edge of two different types of metal sheets. It is a unique type of weld that can be formed in various ways. It’s also used to make corners and T-joints, and joints among the curved and flat metal sheets.

 It is further categorized into five different types of welds.

five different types of welds.
  • Square Groove Welds is created by making a partition within the metal edges or two metal frames. The diameter used to make this weld has it on the weld symbol.
  • Bevel Groove Welds are formed by joining the edge of one end of the joint in a way that it creates a barrel groove. It is a perpendicular line that is always drawn at the left side regardless of the weld’s direction.
  • J-Groove Welds: It is created by forming a concave angle in one metal piece, and the other one remains square. The process is similar to the bevel groove joint formation.
  • Flare Groove Welds: Such type of welding material is used to join welds with two or more round parts. The weld’s root opening is present towards the blueprint symbol’s left while the depth appears in individual brackets.
  • V Groove Welds: It is the same as the square weld. The only difference between the two is of the metal edges present on either side or both sides to form a groove. V angle degree and the ending point of the root are located on the weld symbol.


Plug and Slot Welds

These welds are used to connect the metal frames and sheets that overlap with each other. As both of them have holes, so individual metal sheets with plugs are used to bind the sheets properly. Here, welding metal is placed inside the holes, and welding is fixed with the base metals to form a hard joint.

Bottom Line

To conclude, it’s of great importance to learn the welding blueprints and symbols. If you successfully read the welding blueprints and symbols, you won’t get confused during any construction process stage. However, if you don’t, then you’ve to face adverse effects.

Blueprints and symbols lay the foundation for any project. The designs and logos might be of varying size depending on the nature of the project. Without understanding these diagrams, you won’t be able to complete your tasks promptly.  Take some time and learn to read blueprints symbols. Hire a professional trainer to help you in memorizing these symbols.

 You can also keep the welding symbols chart for reference with you on the fieldwork. Although during the start you will face problems with the time you become proficient in it. Towards the end, we can only hope that this guide will help you a lot in reading the blueprints and symbols. Don’t lose hope and good luck!

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