What Is Butt Welding – Everything You Should Know

Welding can be a very exciting job. Using various welding methods, you can turn some pieces of junk into something creative and useful. But emerging into the welding field requires proper knowledge of different welding techniques and their usages. Butt welding is one example of that.

Butt welding is a welding method that people use in order to join pipelines. They can also be used in other structures. The weld goes in a circumferential motion. Both the base metal and weld metal stays on and within the same plane surface.

It means that the metals will be almost parallel to each other. In this article, we will talk about butt welding in-depth and mention any relevant necessary information.

Why Is It Called Butt Weld?

If you narrow down the continuous weld types, they come down to two weld styles, the fillet weld, and the butt weld. It is one of the most common welding people use to join a plain base metal with another metal. Depending on the weld style, one should make a groove on the base metal where the weld metal will be placed.

In a butt joint set-up, there will be two metals fixed on one another, keeping a gap of 1/8 inches. You need to prepare the grooves based on the metal thickness or dimension. There are groove designs like J, V, or U. You can go for square butt joints for thinner metals.

What Are the Different Types of Butt Weld?

Depending on the weld groove and metal thickness, there are several butt welds methods. Almost all of them work the same way. They are positioned end-to-end with the weld metal through the base metal. Here are some of the butt weld types..

Square Butt Weld- It is for weld metals up to a thickness of 3/16 inches. The metals will be joined side-to-side, and there should be enough gap between the metals for the filler material to flow.

Groove Butt Weld- The groove butt weld is for thick weld metals over 3/16 inches. You make the groove to increase the joint strength. There are two types of groove welds too. The one-sided groove weld is for weld-metal with less thickness. Double-sided ones are for thicker weld metals. However, the grooves must have the proper dimension, not too narrow or too wide.

V Butt Weld- Here, there will be a V-shaped groove. But the base metal will be at least ¼ inches up to ¾ inches thick. You can make the base metal ready using a beveling machine. Remember that the bevel angle for plates is 60-degree and pipes is 75-degree.

Double-V Butt Weld- It is similar to V butt welds, except there will be V grooves on both sides. Suitable for base metals with a thickness of over ¾ inches, they can also be done on thinner metals with critical load strength. Only when you are done welding one side and cooling it should you move to the other side.

Is Butt Weld Better Than Fillet Weld?

It depends on various matters. We can’t just say one is better than the other as they have their own advantages in certain conditions.

Advantages of Butt Weld Over Fillet Weld

Butt welds usually create stronger fusions if everything is done rightly.
Butt welding is easy to perform and machine than fillet.
Butt welds have much control over distortion.
It is easy to monitor the welds too.

Advantages of Fillet Weld Over Butt Weld

You can join surfaces with a 90-degree angle.
Fillet weld takes a lower cost than butt weld.
The fundamentals of fillet weld are easy to understand and master.

How Is Butt Welding Done?

We have put the method of a butt welding process below. Depending on the type of butt welding, you may need to create different grooves or bevels.

First, you should bring two metals and mount them steadily.
It is necessary to keep a gap of 1/8 inches between the metals.
By striking an arc, you should use the filler to fill the gap.
As the filler creates a molten metal pool, it needs to be run along the weld length. Meanwhile, you should add more filler material on the way.
The gap will be there to let the molten metal go through the base metals deeply. So, it needs to have an accurate size.
However, the gap may also depend on the metal’s thickness. For thick metals over 3/16 inches, this gap should be a bit bigger. It can be achieved by chamfering the edges of base metals. For pretty thin metals, the gap may not be necessary at all.
During the weld, you can inspect the weld to ensure everything is perfect before moving to the next spot. In the end, let the joint cool down.

Frequently Asked Questions

1. What Is the Standard for a Welding Bevel?

You can say that the standard for welding bevel is an angle of 37.5-degrees. It doesn’t matter at what level the bevel is. Keep the angle within the tolerance limit. In that way, you can get an excellent weld outcome.

2. What Are the Differences Between Butt Welding and Socket Welding?

Even though both are used for weld piping lines in most cases, there are several differences between them. Butt welding has a higher strength than socket welding. Socket welding is suitable for pipes with lesser diameter. It is easier to detect any leakage on socket welding, but it is costlier than butt welding.

Final Note

Even after being a basic welding technique, butt welding has a number of variations. They are there for metals with different thicknesses. Thus, butt welding has lots of applications and can help you in many ways if you master all the butt weld types.

Never forget to pay attention to the lengths and dimensions of the joint and gap while performing a butt weld. We will also advise you to learn other butt weld techniques like resistance butt welding or flash butt welding.

Last Updated on 2 years by Richard Boyer

Richard Boyer

Richard Boyer has been a professional welder for over 27 years of his life, and now he is a trainer and blogger providing critical information to anyone interested in welding. He is helping out both hobbyists, novice and professional welders to learn newer and better techniques. Read more about me

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