Types of Joints in Welding: Boost Your Welding Knowledge

For an intense-looking kind of job, you probably won’t expect how careful you need to be in welding.

Intricate, if you will.

Because before you could even consider yourself a professional, learning to appreciate and familiarize yourself with how to manipulate metal to fit the blueprints you have in front of you are must-have qualities!

And in welding, merging two different pieces of metal is one you’ll need to practice a lot because, well, that’s what you’d normally do throughout your welding career.

But it’s going to be harder than you’d think, especially once you know there is a TON of ways to merge materials!

And you’ll learn all about them right here!

What Are Joints in Welding?

When merging base materials, you’ll need to have your “glue” to make it happen, right?

In this case, you have your filler metal as the glue, so all you need to figure out is how exactly you would merge them.

That’s where the welding joint comes in!

A welding joint is where you apply your glue (the filler metal) and the point where the other piece fuses with it.

And knowing which one to use for different situations can keep it nice and neat while providing a strong bond!

Types of Joint in Welding

Butt Joint

No, the weld won’t look like a pair of butt cheeks, so get that thought out of your head.

But the pieces you’re going to weld DO act a lot like butt cheeks, though!

Just like anyone’s behind, the metal pieces you’re going to merge here are placed together on the same flat surface.

This way, you now have the edges of either metal meet end to end!

But other than having the edges in contact with each other, you can even allow free space in between!

It’s why you can normally see this be used on grooved weld types, such as square groove, V groove, bevel groove, flare-V groove, U groove, and J groove.

However, although it’s the most straightforward of the welding joints, you’ll need to take extra care in welding because you need to get your filler deep into that opening to penetrate the metal entirely.

So, here’s a tip: prep up your metal pieces by modifying the edges of the metal pieces.

Either your client will provide you with the dimensions or you have to make them yourself, whichever your situation is, modifying the edges will give you a better shot at fully penetrating your metal.

Once you got that down to a science, you can begin welding using a small amount of filler to be much more thorough!

Corner Joint

Metal boxes, and frames—using corner joints is the norm for sheet metal applications like these.

At exactly 90 degrees, the two metal pieces are placed together with the area at the corner open so the parts where you’re going to join them together form an “L” using the welding joint.

Due to how common the corner joint is, knowing plenty of weld types would be extremely useful in this case because, here, you’ll be using this on both grooves AND fillet welds!

Namely, J groove, V groove, square groove, spot weld, edge weld, corner flanges, and flare-V grooves.

Edge Joint

It’s only mentioned as one of the examples where you can use corner joints, but this is its time to shine!

Instead of edge welds, what we have here is the edge joint!

Now, the edge joint is most likely the most difficult out of all these welding joints.

Then again, everyone’s built differently, so maybe you’ll find this easier while other welding joints are harder. Who knows?

Anyway, edge joints are done along the edges of two metal pieces (usually metal sheets) that are placed parallel to each other to even out the edges.

What made this the most difficult welding joint is how every single thing you do to your last weld can easily affect your edge joint.

And with how thin metal sheets are, you bet joining these two pieces together will bring in some challenges!

But be aware that, despite evenly distributing the metals’ stresses, this doesn’t make it the strongest joint in the bunch because your weld won’t be able to penetrate something as thick as the area where these metals touch each other.

Where you’ll usually see this joint be used are on J grooves, V grooves, U grooves, bevel grooves, corner flanges, and edge flanges.

Tee Joint

So, while the corner joint only has the corner being joined together, the tee joint technically has TWO corners fused!

How does this happen, we have two metal pieces.

Now, one of those pieces would be on top of the other but, unlike the lap joint, that upper piece should have 90 degrees on either side with the lower piece as its base metal.

Therefore, forming a “T” shape smack-dab in the middle!

What you want to happen now is you’ll only join one side (or two, depending on your instructions) of the upper piece to the base metal.

Of course, because the upper piece is standing all alone in the middle of its base, you might see it warping more to the side where you welded on. 

But it’s nothing a few braces can’t fix. This way, you can be sure your upper metal will stay in place!

Normally, you’ll see this be used on fillet welds (like plug weld and slot weld), but there are grooves wherein you can join them that might resemble fillet welds a bit (like J groove and bevel groove) with flare-V groove the only exception.

Lap Joint

types of welding joints

Lastly, the lap joint.

Coming from the word “overlap”, the lap joint has two pieces of metal on top of each other so these pieces can, well, overlap one another!

Now, in situations when both of your base metals have different thicknesses, you can just flip it over once you’re done with the top side so you could join its underside, as well!

That’s double the strength of joints!

So, just like the tee joint, it’s more usual to see the lap joint be used on fillet welds, but that doesn’t mean you can’t use it on the bevel groove and J groove, too.

Final Words

Knowing how to weld these different joints leaves you equipped to handle most of what’s required from the instructions given to you.

But familiarizing yourself with them? Training yourself for improvement until you can weld these with your eyes closed?

That’s what you call a dedicated welder! Know more about different types of welding machines to make it much easier.

And you bet this level of care and attention you have on your metal and welder will attract all sorts of clients that can boost your reputation! Cheers!

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