If you are looking to join welders professionally, as a hobbyist, or for any other reason, it’s vital to start by learning all the basic welding joint types.
A weld joint is a point where two metals meet. Depending on which of the five welding joint types a welder chooses, it will have a long-term effect on how well the piece performs its intended use.
Welding Joint Types
- Butt Joint
- Corner Joint
- Tee Joint
- Edge Joint
- Lap Joint
The 5 Welding Joint Types
Each welding joint type serves a specific function and is appropriate for different circumstances. Successfully choosing the proper joint is essential to creating a durable weld that will hold up to wear and tear.
There are several different welding styles within the primary five welding joint types. As we explore the broader categories, we’ll also look at the specific techniques that create the different styles.
Butt Joint
Butt joints are where the two welding surfaces push up against each other end to end to make a flush, level surface. These joint types are common in piping, tubing, plating, and other applications requiring a smooth weld.
Depending on the result you are trying to achieve, you can employ many different styles of the butt joint. The differences come down to the type of angle.
- Square
- A square butt joint is when you weld two surfaces together end-to-end. There is no bevel, so it’s best for projects that include thinner metals.
- Single bevel
- A single bevel involves cutting one end at an angle to the other, so the weld is recessed between the two ends.
- Double bevel
- A double bevel is when one end is beveled to a point; two angles meet at the end. The weld forms a slight “Pacman” shape.
- Single J
- A single J joint is remarkably similar to a single bevel, but the end is curved rather than straight.
- Double J
- Double Js are the same as singles, but there’s a curve to the bevel. Both ends get cut into curved slants forming a U recess for the weld.
- Single V
- A single V is like two single bevels end to end to form a V-shaped recess.
- Double V
- A double V is like putting two double bevels end-to-end, creating an hourglass shape. The double V style leaves recesses on both sides of the weld.
- Single U
- A single U is like a single V but it has a U-shaped recess.
- Double U
- A double U is Just like the double V style, except that the recess shape here is a U shape.
Corner Joint
Corner joints are a vital joint style for attaching two surfaces at 90-degree angles forming an L shape. They are commonly found in frames, structures, and edges of projects.
There are two categories of corner joints, open and closed. Open corners entail that you can see the end thickness of each piece, whereas, in closed corners, one end is flush against the surface of the other.
Within these categories, there are a few styles of corner joints. Here are the main ones.
- Flush End
- A flush end corner weld is one where you have thin material with the end of one piece flush to the surface of the other and make a weld on the outside where they meet.
- Single V
- A single V is when the end of the joining piece is beveled so that when it is brought to the surface of the other piece, it forms a sort of V recess.
- Single V and Fillet
- The single V and fillet consist of a single V weld, but you also weld on the inside of the corner to reinforce the joint.
- Single Fillet
- A single fillet is an interesting joint. Both pieces are close but not touching aside from their inner corners. You then weld between them in the wide V that their ends leave. This style is like a double V but doesn’t require cutting bevels.
Tee Joint
A tee joint is like a corner joint, but instead of connecting the ends, one end sits perpendicular to the surface of another piece, creating two 90-degree angles on either side of the adjoining piece.
Tee joints are an integral part of many systems that need high-strength joints like structural steel, tubing, and machinery.
Tee joints can be very simple, but there are still a few different ways to weld them.
- Double Fillet
- A double fillet is simply welding on either side of the connecting end without making bevels.
- Single Bevel
- The end is beveled at an angle to allow a V recess between the end and surface.
- Double Bevel
- A double bevel turns the joining end into a point and leaves recesses on both sides for the weld, making the whole joint neater than a double fillet.
- Double J
- This joint is the same as a double bevel, but the cut angles are curved instead of straight.
Edge Joint
Edge joints are useful for joining two parallel surfaces. These joints are vital to high-impact structures thanks to their added strength compared to other types of joints.
There are just a few types of edge joints; here are two.
- Square
- The square edge joint is simply a flat weld over the connecting end surfaces.
- Single V
- The single V involves cutting a slant on both ends so that when they are put side by side, they form a V at the end. The weld sits in this recess.
Lap Joint
A lap joint is necessary when you join two surfaces face to face, but the ends don’t line up. These joints are perfect for joining plates of sheet metal and thickening structures.
The two types of lap joints are defined by whether you weld one or both sides of the adjoining metals
- Single Fillet
- For this one, you weld one end to where it touches the surface of the other piece.
- Double Fillet
- A double fillet is the same as a single fillet, but you weld on both sides, welding both ends to both surfaces.
Wrapping Up
While this article covers all the essential joints and welds, there are many more styles and types. Practice definitely makes perfect when it comes to welding, so try your hand at all of the different welding joint types to ensure a flawless finish.
