Types of Welding Joints | Symbols | Applications | Advantages | Disadvantages

Before going into the depth of the types of welding joints it is necessary to understand why different welding joints are necessary. The main reason behind the various types of welding joints is the uniqueness of each joint.

Few joints are useful for lightweight metals & few for heavy metals. Few produce strong welds consequently they are complex while others are cheap & produce mild welds. Every joint has its own unique applications, pros & cons.

A detailed article is given below to understand how they vary from each other & their symbols with real-world applications. 

Table of Contents

Joint Definition according to “AMERICAN WELDING SOCIETY”

The manner in which materials fit together is called as Joint”.

What is Welding?

“Welding is the process of joining two pieces of metal together so that bonding takes place at the ends of joining surface”.

What is Welding Joint?

“A welding joint is a common point or edge where two or more workpieces of plastic or metal are joined. These workpieces are joined using different types of welding processes”.

Joints Preparation

Sometimes before the welding process is started joints preparation is necessary. Various techniques are used for joints early preparation. These techniques may include

  • Routing
  • Stamping
  • Shearing
  • Casting
  • ForgingMachining
  • Filing
  • Plasma Arc Cutting
  • Oxyacetylene Cutting
  • Grinding

Comprehensive INFOGRAPHIC about Types of Welding Joints

Infographic-Types of welding Joints

Download Types of welding joints PDF from HERE

Types of Welding Joints referred by “American Welding Society”

Basically, there are 5 types of welding joints which are given below.

  1. Butt Joint
  2. Corner Joint
  3. Edge Joint
  4. Lap Joint
  5. Tee Joint

(1) Butt Joint

The type of joint in which two metal pieces are joined in the same plane is called as a butt joint. Butt joints are used to weld thin metal sheets which can be welded in a single pass. These welds require some kind of preparation as well.

Butt joint Symbol

Butt Joint-The Welding World

Real World Example Butt Joint

BUTT joint real world example-types of welding joints

Common issues Associated with Butt Welds

Weakness behind any butt welded joint is because of the following reasons.

  • Slag entrapment
  • Excessive porosity
  • Cracking

How to achieve Strong Butt welded Joints?

Use less welding material as much as possible to obtain strong welded butt joints.

When are Butt Welds best to Use?

  1. Butt welds are best when they are used with automated processes like submerged arc welding process (SAW) because their preparation is relatively much easy.
  2. Also, when human guidance is not necessary i.e. there is no need for an operator for adjustment in non-ideal joint preparation.

Types of Butt Joints

  • Single welded butt joint
  • Double welded butt joint
  • Open welded butt joint
  • Closed welded butt joint

(i)Single Welded Butt Joint

The joint which has been welded from one side is called as a single welded joint.

(ii)Double Welded Butt Joint

The joint which has been welded from both sides is called as a double welded joint.

(iii)Open Welded Butt Joint

The joint which has a small gap between the workpieces when being joined is called an open welded joint.

(iv)Closed Welded Butt Joint

The type of joint in which the two workpieces are touching during the welding is called as a closed welded joint.

Welding styles used to create Butt Joints

  • Bevel Groove butt weld
  • Square groove butt weld
  • V groove butt weld
  • J groove butt weld
  • U groove butt weld
  • Flare bevel groove butt weld
  • Flare V groove butt weld

Advantages & Disadvantages of Butt Welding Joint

Advantages
  • Universally accepted method
  • Easiest welding method
  • Most common method
  • Very affordable/cheap method
Disadvantages
  • Chances of porosity in butt welds
  • Edge preparation is required while working with thick metal pieces

Applications of Butt Welding Joint

Applications

Its applications include

  • Pipes
  • Valves
  • Flanges
  • Fittings

(2) Corner Joint

The type of joint that is formed by placing the corner of two parts at a right angle to each other is called a corner joint. As a result, an L shape is formed between the two parts that are being joined. This technique is one of the most popular to join metal sheets. This is used on the outer edge of the sheet.

Corner joint Symbol

Corner Joint-The Welding World

Real World Example Corner Joint

CORNER joint real world example-types of welding joints

Types of Corner Joints

  • Flush Corner Joint
  • Half Open Corner Joint
  • Full Open Corner Joint

(i)Flush corner Joint

Flush corner joint is primarily designed for welding metal sheets which are equal to 12 gauges or thinner than this. Deep penetration is difficult most of the times as a result design can afford moderate loads.

(ii)Half Open corner Joint

Half open corner joints are primarily used for welding materials which are heavier than 12 gauges. Penetration is better than a flush corner joint but only used for moderate loads.

(iii)Full Open Corner Joint

Full open corner joint is primarily used for producing strong joints especially when welding is done on both sides of the materials. Therefore Mostly useful for welding plates of all thicknesses i.e. thinner or thicker.

Welding styles used to create Corner Joints

  • Edge weld
  • Bevel Grooved weld
  • Corner Flange weld
  • Fillet Weld
  • J-Groove weld
  • Flare V groove weld
  • Spot weld
  • Square groove weld
  • Butt weld
  • U-groove weld
  • V-groove weld

Advantages & Disadvantages of Corner Welding Joint

Advantages
  • Strong welds can be produced
  • Variety of Welds is possible i.e. thinner/thicker
  • The most popular technique to join metal sheets
Disadvantages
  • In a corner joint, there is a chance of Increased Wear & Tear

Applications of Corner Welding Joint

Applications

Its applications include

  • Corner joints are used for sheet metal that is used to attach pieces together for creating different shapes.
  • For welding light sheets of metal where strength is not necessary a close corner joint may be used.
  • For heavier metal sheets welding is done on one side of the heavy metal to form a half corner joint.
  • This technique is also useful in the construction of boxes, box frames & another similar type of fabrication.

(3) Edge Joint

The type of joint that is formed by welding edges of two different parts together is called an edge joint.

Edge Joint Symbol

Edge Joint-The Welding World

Real World Example Edge Joint

EDGE joint real world example-types of welding joints

Welding styles used to create Edge Joints

  • U-Groove weld
  • V- Groove weld
  • J- Groove weld
  • Bevel Groove Weld
  • Edge-flange Weld
  • Corner flange Weld
  • Square-groove weld/butt weld


Advantages & Disadvantages of Edge Welding Joint

Advantages
  • Useful for sheets less than 3mm thicker
  • No preparation is required for this weld joint
  • The filler material is not required to fuse the sheets together
Disadvantages
  • Weld doesn’t penetrate completely at the joint thickness
  • This welding joint type can’t be used in stress & pressure applications
  • Edge welds are not as common as other weld joint types
  • These joints are mostly replaced with other joints due to build up accumulating on the edges
  • Very rarely used joints technique

Applications of Edge Welding Joint

Applications

Its applications include

  • This welding joint is mainly used where edges of sheets are adjacent & are approximately parallel planes at the welding point.
  • These joints are most commonly used for parts of metals that have flanging up edges or where the weld is necessary to join two adjacent pieces together.
  • Edge welds are most commonly used for those materials where sheets are less than 3mm thicker.
  • Flanged joint with edge welding is also used in automotive gas tanks & assembly housing.
  • This welded joint is common in aerospace repairing world.

(4) Lap Joint

The type of joint in which two workpieces are placed at each other i.e. one above the other is called a lap joint. Lap weld joint is formed when pieces are placed at overlapping positions.

Lap joint may be

  1. One-sided
  2. Double Sided

Lap joint welded on double sides provides strength as compared to one-sided weld because no material is removed from both of the sheets that are being joined.

This welding joint is useful when metal sheets of different thicknesses are being used.

Lap Joint Symbol

Lap Joint-The Welding World

Real World Example lap Joint

LAP joint real world example-types of welding joints

Welding styles used to create Lap Joints

  • Fillet Weld
  • Bevel-groove Weld
  • Slot weld
  • Plug weld
  • Spot weld
  • Flare-bevel–groove weld
  • J-groove weld

Advantages & Disadvantages of Lap Welding Joint

Advantages
  • Satisfactory lap weld is obtained easily i.e. not difficult technique
  • No risk of blowing through the weld joint because the second sheet is present on the other side of joint
  • Lap joints are quicker & simple to be made
  • Stronger welded joints are obtained if a double-sided weld is made
Disadvantages
  • Sheets bearing heavy loads can’t bear one-sided lap weld

Applications of Lap Welding Joint

Applications

Its applications include

  • Lap weld joint is most commonly used in resistance spot welding, gas tungsten arc weld & gas metal arc welding. High energy weld processes are not usually used in lap weld like electron beam or laser beam weld.
  • Lap joints are also applicable in plastic & wood.
  • Lap welds are commonly used in automation involving processes. They are also used in
    • Tabling
    • Temporary framing
    • Frame assembly in cabinet making

 

(5) Tee Joint

The type of joint in which the two parts intersect each other at right angle i.e. 90 degrees & one part is above the other at the center is called as T joint.

The metal surface that is being joined is never on the same plane.

An approximate shape of English letter “T” is obtained hence named as T joint. T joints are also considered as a type of fillet weld.

Tee-Joint Symbol

Tee Joint-The Welding World

Real World Example Tee Joint

TEE joint real world example-types of welding joints

Welding styles used to create Tee Joints

  • Fillet Weld
  • Flare-bevel groove
  • Plug weld
  • J-groove weld
  • Slot weld
  • Bevel-groove weld
  • Melt-through weld

Advantages & Disadvantages of Tee Welding Joint

Advantages
  • No preparation needed in case of plain TEE joint
Disadvantages
  • Extra care is necessary to ensure effective penetration on weld roof
  • Corrosion fatigue is common in T welded joints
  • Due to geometry generated by T joints, they may contain increased cracking, moisture entrapment, excess porosity, corrosion

Applications of Tee Welding Joint

Applications

Its applications include

  • T welded joints are used when a metal piece is attached to some sort of a base
  • T joints have found its use in structural and machine applications
  • A single beveled joint is used in thin plates which can be welded from one side, usually used for joining thin plates
  • A double beveled joint is used in heavy plates which can be welded from both sides

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Conclusion

Now after studying all the different types of welding joints, we can decide what joint to use when we have different requirements. Now we are in a situation where we can decide what joint to use when we need stronger welds. We can also decide what joint to use when we don’t need ideal conditions. This thorough guide on types of welding joints helps us to understand the differences between joints keeping their pros & cons & applications in front.

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Summary
Types of Welding Joints | Symbols | Applications | Advantages | Disadvantages
Article Name
Types of Welding Joints | Symbols | Applications | Advantages | Disadvantages
Description
According to AMERICAN WELDING SOCIETY, there are 5 types of welding joints that include BUTT joint, CORNER joint, EDGE joint, LAP joint, TEE joint.
Author
Publisher Name
The Welding World
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