Corner Joint Welding- The Basics You Need to Know

Corner Joint Welding Definition

Corner Joint Welding is a process of joining two parts at a 90-Degree angle (right angle), making an L-Shape joint. This type of welding is commonly used to join metal sheets together, as well as pipes and other tubular materials.

Corner weld is similar to a T-weld joint except that one end is connected to form a L-shape & parts are joined at the corner, giving the name as Corner Joint. Corner joints are widely used in machine design and box members. The weld joint preparation is nil to bevel types in a corner weld. You can notice corner welds in tanks, frames, machine parts, etc.

Typical corner designs are illustrated in below diagram.

Corner Joints

Open corner joint or also called corner-to-corner joint in figure (A) is difficult to position. So, fixturing arrangement is needed for such joint. Also, first pass welding call for small electrodes that need minimal welding currents. In addition, they require a large amount of weld metal.

Types of Corner Joint

There are many different types of corner joints that can be used when joining two pieces of wood together. The most common type of joints are:

  1. Closed Corner Weld Joint (Flush Corner Joint)
  2. Open Corner Weld Joint (Fillet Weld Corner Joint)
  3. Half open Corner Weld joint
  4. Flanged Corner Weld joint or also called Edge Weld Joint
Types of Corner joints

Different types of corner joints are used in engineering. An open corner joints are welded as a fillet weld and hence not suitable for high loading or stress applications. Half corner joint also has similar restrictions due to limited depth of welding fusion. Half corner joint is a PJP weld. Although a closed corner joint welded with a full bevel can withstand high stresses and loading.

These joints also provide leak proof weld if followed with 100% NDT. A closed corner joint with through thickness weld bevel is a CJP weld joint.

Closed Corner Weld Joint

Closed corner joint example is given below. Closed Corner welding joints are used for thick sections. They are usually made with weld bevel, either partial or full penetration weld (PJP or CJP).  The weld bevel can be V-Groove, J-Groove or U-Groove.

A fillet weld also generally made on closed corner weld joint from inside to provide a leak proof, strong, neat and economical corner weld joint. The thickness of the weld should be calculated based on the thinner member’s thickness, as the joint is only as strong as the thinner member. Therefore, weld metal requirements can be reduced, resulting in cost savings.

Open Corner Weld Joint (Fillet Weld Corner Joint)

Open corner welding joint example is given below. Open corner weld joints are useful for welding thin sheet metal or gauge sheets. This is also called corner-to-corner joint. Open corner joints are difficult to position (fitment) and hence requires use of fixturing. Welding is carried out using small diameter electrodes with low welding setting to avoid excessive melt-through. Due to large weld volume to fill the joint, higher weld metal is consumed in open corner weld.

Half Open Corner Weld Joint

Half open corner weld joint is easy to assemble, require no weld backing and need only about half of weld metal compared to open corner joint. Due to reduced welding throat size, half corner joints are having lower weld strength compared to open corner joint.

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These joints can be welded with additional fillet weld from inside to increase the strength but need weld accessibility from inside. These joints are not used for thin sheet metals and usually beneficial for 1/8-inch and higher plater thickness.

Flanged Corner Weld joint

Flange corner joint is a type of edge weld. It is a form of a corner joint where the butting part has a flanged edge shape at the weld joint. The welding is carried out like a edge weld.

Corner Joint Welding Symbol

A Corner joint welding symbol is a graphical representation of a welded joint. The type of corner joint (Open, closed or half close, for example) will determine the weld symbol used.

 An open corner has a fillet weld symbol, while a closed corner has either a groove or fillet weld symbol. The size and number of welds required will also be indicated on the drawing.

A corner joint welding symbol is used to denote the type of corner joint being welded. The most common types of corner joints are open corners as a fillet weld & CJP and PJP on closed corner welds. Each type of corner joint has its own welding symbol.

Corner weld joint symbols with fillet on back side

An open corner has a fillet weld symbol next to it, indicating that a fillet weld will be used to join the two pieces of metal.  Closed corner weld can be either square groove, V-Groove, J-Groove or U-groove based on weld bevel preparation.

Additional fillet weld if any on inside will be specified as fillet weld on other of the welding symbol.

Corner Joint Welding Diagram

A corner joint welding diagram is a great way to visualize the weld joint while you are welding. The diagram will help you to see how the weld joint should look when it is completed. There are a few things that you need to keep in mind when you are looking at a corner joint welding diagram.

Corner Welding joint diagrams

First, the diagram is not always drawn to scale. This means that you need to pay attention to the dimensions of the weld joint on the drawing.

Second, the drawing may not show all of the features of the weld joint that you need to know about. For example, the drawing may not show any bevels or chamfers on the edges of the plate. These features can be important when you are welding thin plates together.

Finally, make sure that you understand all of the symbols and abbreviations used on the drawing before you start welding.

Corner Joint Welding Advantages

Corner joint welding is a type of welding that is used to join two pieces of metal at a corner. This type of welding is often used for applications where two pieces of metal need to be joined at a right angle, such as in the construction of metal buildings or in the fabrication of machinery.

 There are several advantages to using corner joint welding, including the following:

  • Corner joint welding provides a strong and reliable connection between two pieces of metal.
  • Corner joint welding is a relatively quick and easy way to join two pieces of metal.
  • Corner Joint Welding is easy to assemble.
  • Corner Joint Welding is easier to automate than other methods.
  • Corner Joint Welding can be used in a variety of materials including metals, wood, and composites.
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Corner Joint Welding Disadvantages

Corner joint welding is a type of welding where two pieces of metal are joined together at an angle, usually at 90 degrees. While this method of welding has its advantages, there are also some disadvantages that should be considered before using it.

  • One disadvantage of corner joint welding is that it can be difficult to achieve a good weld. This is because the angle of the weld can make it difficult to get the right amount of heat and pressure on the metal. This can lead to a weld that is not strong enough or one that has gaps.
  • Another disadvantage of corner joint welding is that it can be hard to create a smooth finish. This is because the angle of the weld can create ridges or bumps on the surface of the metal. This can make it difficult to paint or finish the metal surface evenly.
  • Another downside to Corner Joint Welding is that it can be time-consuming, especially in open corner joint.
  • This method often requires multiple passes to ensure a strong weld, which can lengthen the overall completion time.

Which type of Corner Joints are good to avoid Lamellar Tearing?

Open corner joints distribute the stress on both members and beneficial to avoid lamellar tearing. If closed corner joints are used, they shall be provided beveling of the joining edges to reduce the lamellar tearing tendency.

Types of Welds in a corner weld

A Corner weld joint can have different weld configurations based on the edge preparations. Below are the main types of welding types possible in a corner joint welding:

  1. Fillet Weld– E.g., an open corner joint weld
  2. Bevel Groove Weld– V-groove, J-Groove, Square groove & U Groove- Possible with a closed Corner Joint welding
  3. Plug weld– Also in a closed corner joint

What is the difference between corner joint and tee joint?

A Corner joint is assembled by placing the two parts at right angle to each other at corners while in Tee joint, parts are placed perpendicular to each other forming T-shape. T-joints are very common than the corner joints.

T-joints are also easy to make as no special fixturing or arrangement is needed while in a corner joint, extra precautions is required to ensure a good assembly for welding or joining.

What are the uses of Corner Joint?

Corner joints are an essential part of any woodworking project. They are used to join two pieces of wood at a 90 degree angle, and can be either square or mitered. Miter cuts are generally used for decorative purposes, while square cuts are more functional.

Corner joints are also widely used in welding and fabrications applications. They are used to join two pieces of metal at right angles to each other, and can be used on a variety of materials including steel, aluminum, and stainless steel. They are used in machine parts, box members, sheet metal welding and structural applications.

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Corner Joint Welding Procedure

Corner welding joint require a established procedure with detailed instructions for the use of fixturing, clamping and other devices. In general you can follow welding procedure for corner welds:

  1. Decide the type of corner joint based on material thickness. Use open corner for thin material, half open corner joint or closed corner joint for higher thickness. Closed corner is used for larger thicknesses.
  2. Next, you will need to clean the area around the joint that you will be welding. This is important in order to ensure a strong weld.
  3. Once the area is clean, you can begin welding the joint. Start by running a bead of weld along one side of the joint, then move to the other side and do the same thing to weld additional fillet weld from inside.
  4. For thin sheet metal, use autogenous tig welding to melt the edges. For higher thickness, you can use stick welding, mig Welding or tig welding. Use fixturing and clamps for smaller thickness to prevent weld distortion.
  5. Root run must be welded with low welding setting to prevent burn through. This is especially a concern for smaller thickness.
  6. Continue welding until the entire joint is covered with weld material. Then, allow the weld to cool before moving on to the next step.
  7. Finally, you will need to grind down the weld material in order to create a smooth, flush surface.

Corner Joint in Woodworking

A corner joint is a type of woodworking joint used to join two pieces of wood at right angles (90° angle). It is one of the most basic and essential joints in woodworking and can be found in everything from furniture to framing.

The most common way to create a corner joint is by using a drill and dowel. Drilling a hole into each piece of wood to be joined, then inserting a dowel into the holes so that the two pieces are connected.

The dowel should be slightly longer than the width of the hole. This will allow the glue to adhere properly and create a strong bond.


Another way to create a corner joint is by using screws. This method is more common when joining thicker pieces of wood together. The screws will go through both pieces of wood and then be secured with nuts on the other side. This creates a very strong connection that can withstand a lot of weight and force.

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