Building has always been the profession of creatives in every era of human history. Whether that be the building of the pyramids, the Eiffel Tower, or the Empire State building, every type of constructive truly is an art form. In current times, our most commonly used building materials are concrete and steel.
Considering building with steel, we could not accomplish it without expert welders who make possible all the wonderful structures, products, and other physical items that we enjoy in our age of human history. So, what do welders know that the typical citizen may not be aware of? Well, the very first thing that comes to mind is the specific welds that are possible, and the two fundamental types of these welds are the fillet weld and the butt weld. Butt welding is typically combining two peices of metals together, usually done on pipes.
Today let’s inspect what is a butt weld, specifically and figure out what it does, and what the distinct types or techniques of butt welding are possible. The first area that is important to talk about is what really is a butt welding and the differences between the joints?
What Is Butt Welding?
Well, when talking about this type of weld, we are looking at the way we join together two metal pieces. What is a butt weld? A butt weld is an common welding joint that combines two pieces or sheets of metal end to end, that are leveled, i.e. on the same axis and/or parallel to one another. The two pieces are typically flat surfaces/circular pipes that are combined to become a strong single piece of metal through the correct application of butt weld techniques, of which there are four main types. These types of butt welds are the square joint, v joint, u joint, and the j joint.
To create a strong butt weld you first choose the proper joint type needed to make sure you achieve full penetration of both metal faces and that the gap between the two, typically set at about 1/8th of an inch apart, can be filled fully with whatever your filler material is while maintaining the proper angle.
Once prepared, you will simply create an arc and heat up a point between the two pieces until they both become molten. Then, while adding filler material to the gap and maintaining the molten pool, you push at the proper angle and move the pool along the entire seam evenly. Once you reach the end you should have pushed out any contaminants into the upset and have created one continuous and single piece of metal out of your original two sides of material.
When done correctly the butt welding finish is smooth and pleasing surface without unnecessary grinding or brushing to remove uneven areas in your welded seam. Both sides of front and back will have an equally smooth face, that only the perfect butt weld can create.
Single-sided welding is when the welds are done from one area.
Double-sided welding is when the welds are done on both sides of the material, they require more precision and specific angled cuts in order to have a clean fit. (See the video above at 9:06)
Different Types Of Butt Welding Joints:
The V Joint Butt Weld:The next type of butt weld joint to consider is the simple V joint butt weld. This welding joint is created by cutting or grinding your edges of the material to be joined into a V shape by creating a beveled edge of about 60 degrees into each side of the base material. When put together the gap between the two pieces should make a V shape when viewed from the end of the pieces. This type of joint is best for materials of around a ¼ inch thick or more. This is because it allows for a full penetration into the material, which helps create a stronger weld than would otherwise be possible.
The U Joint Butt Weld:Like the V joint, we use the U joint when combining thicker materials end to end, i.e. butt to butt. This type of joint is made by grinding a curved groove into each side of the material that resembles a C shaped groove on each material's end. When combined, and viewed from the end of the pieces, these two grooves create the U shape that makes up the joint’s namesake. We use this type of butt weld in the connection of thicker metal materials because it offers you the ability to create full penetration. This type takes more filler material to create a strong weld than would a V joint but is sometimes easier to work with, in the long run.
The J Joint Butt Weld:The fourth and final type of butt weld joint is the J joint. This type is the most economical way of combining two thicker pieces of material because you will use less filler material from your welding. This is because the preparation for this type of joint involves only grooving one of the two pieces of metal you are connecting. When making the groove you just grind down one of the two pieces so you create the same shape you would have for a single U joint. Then, when you set the two pieces up to be welded, the gap between them looks like a J up against a straight-sided piece of metal. Since the groove your are going to be filling with welding material is only half the size of a regular U or V joint, it makes this the most economical option for welding together two thicker pieces of metal while maintaining the penetration required to create the strong bond you are seeking.
These are the basic types of butt welds that are considered when we talk about joining two pieces of metal to each other side by side and parallel to one another. There may be other more specialized options or variations of these basic four but knowing these are important in creating strong and reliable welds of parallel pieces of metal.
Benefits of Using a Butt Weld
What are Typical Filling Agents?
In order to create a strong joint between your materials, you will use a vise or clamp to fix them together. Many welders use a class 3 copper solution as their filling equipment of choice, conducting heat very well and giving strength and flexibility to your project.
How Do I Choose The Right One?
If you are looking to join together two different pieces of metal, you definitely will want to use a butt joint weld, but choosing the right kind for your needs is where it gets a little tricky.
Remember, a simple square butt weld is useful for thinner pieces of metal, where you want to use a V-shaped or double V-shaped butt weld for thicker pieces. As you learn about, what is a butt weld and gain more experience in the field, it will be easier for you to make the best possible choice for the different type of joints to preform.