What Are the 4 Basic Welding Positions and When Should You Use Them?

Understanding the four basic welding positions can help you choose the right filler metal and welding process for your job. Each welding position may require different techniques, parameters and preparation to achieve the best results. 

Learn more about the different welding positions and get some best practices for welding each type. 

What are the 4 basic welding positions?

You can perform fillet and groove welds in these basic positions:

• Flat (1)
• Horizontal (2)
• Vertical (3)
• Overhead (4)

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To help operators understand the type of weld joint (fillet or groove) and the weld position, each weld is given a number and a letter — 1G, 2G, 3G, 4G or 1F, 2F, 3F, 4F — to indicate the position and the type of weld required. Welds with a 1 are flat position, 2 is horizontal, 3 is vertical and 4 is overhead. F stands for fillet weld, while G is a groove weld. A fillet weld joins together two pieces of metal that are perpendicular or at an angle. A groove weld is made in a groove between workpieces or between workpiece edges. Using this system, a 2G weld is a groove weld in the horizontal position.

Welders are likely to see these designations in a welding procedure specification (WPS). They are also found on filler metal data sheets, which call out the positional capabilities of specific filler metals.

Filler metal impact on welding position

The filler metal, welding process and transfer mode you use dictate which position you can weld in. Some filler metals are designed for use in all positions, while others are restricted to flat and horizontal only. The filler metal type includes a designation that denotes in what positions it can be used in. For example, a flux-cored electrode may be designated as an E70T-XX or a E71T-XX. The zero in the E70T-XX designates that the electrode can only be used in the flat and horizontal positions, where the 1 in E71T-XX indicates a filler metal that can be used in all positions.

Regarding processes and modes of transfer, here are some general guidelines:

• You can TIG weld in all positions.
• Short-circuit MIG can be done in all positions.
• Use spray transfer MIG for flat and horizontal welding only.
• Pulsed MIG can be used in all positions.
• Stick and flux-cored welding can be used in all positions, but the choice of filler metal is the main driver in this.

Flat welding position

Generally, flat is an easier position to weld in since you’re not fighting gravity. The weld puddle stays fluid and wets into the joint evenly. As a result, operators can typically run hotter with higher deposition rates.

You can use any welding process to weld in the flat position. Just be sure to use the recommended techniques for whichever process you’re using. For example, the stick process produces slag, so consider using a drag technique rather than a push technique.

The proper work angle for a flat position weld will change depending on whether the weldment is a 1G or a 1F. If the wire or electrode is off to one side or the other, the heat won’t be focused where the two pieces come together, and you may get incomplete fusion.

Horizontal welding position

In a horizontal weld, the weld axis is roughly horizontal. Welds in the horizontal position share many similarities with flat position welds.

A 2G weld is slightly more difficult than a 2F weld. The 2F provides a bottom shelf to ensure the weld puddle doesn’t get out of control or sag too much. To combat the effect of gravity on the weld puddle in a horizontal groove weld, favor the top edge of the joint slightly with the work angle, knowing the puddle may sag a bit. In a horizontal fillet weld, keep a 45-degree angle to the joint to focus the heat where the two pieces come together.

Don't run too hot in horizontal welds since a puddle that’s too fluid can fall victim to gravity. Tweak your weld parameters to make sure the puddle doesn’t get too hot or too fluid.

You can also use any of the welding process in the horizontal position.

Vertical welding position

Operators can complete vertical welds in either vertical up (moving bottom to top in the weld joint) or vertical down (moving top to bottom in the weld joint). Vertical up is typically more common, especially on thicker materials. You may need to use this when working on a large weldment that you can't easily move into the flat or horizontal position.

Moving up the plate for a vertical weld, the weld puddle will naturally want to sag out of the joint. If you use the same techniques and parameters ideal for flat and horizontal welds on a vertical weld, it likely won’t produce a quality weld.

Adjust the weld parameters to achieve the best results in vertical welds. Use a reduced wire feed speed and voltage to ensure the puddle does not fall out of the joint. If you’re using a welding power source with Auto-Set™ technology, be sure to use the parameters designed for a thinner material, even if you’re welding thicker base metal. This helps keep the heat input lower to fight gravity.

Use a 90-degree travel angle for a 3G weld, and a 45-degree angle for a 3F weld.

Slowly manipulate the puddle in a way that washes it to each edge of the joint. Going straight up with a vertical weld will typically result in a ropey bead that doesn’t wash into the edges well. Instead, hold the toes of the weld longer and quickly move across the middle of the puddle as you travel up. Welders can use several common techniques for this puddle manipulation — including a zigzag motion, an upside-down T or repeated triangles stacked on top of each other — depending on the operator's preference.

In vertical welding, it’s important to make sure you’re in a comfortable position before starting to weld. Practice first on scrap material to make sure the parameters and technique you’re using produce the results you want. That way you can make adjustments before welding your workpiece.

Overhead welding position

Overhead welds may be required when you’re working on a fixed piece of equipment or metal that cannot be moved. Operators may find themselves lying on the ground or floor of their shop for overhead welding, so it’s important to find the most comfortable position with a range of motion.

The same techniques used for vertical welding often apply to overhead welding. A 4G weld will require a slight weave or manipulation of the weld puddle to wash in at the toes better, just as with a vertical weld. You'll also want to dial back parameters to run cooler with overhead welds, since you don’t want a weld puddle that is too fluid that will fall out of the weld joint and onto you.

When welding in the overhead position, sparks will drop down. You may want extra protection on the top of your head, such as a bandana under your welding helmet. Use a fully leather welding jacket, especially with a process like stick welding, which produces more sparks and spatter.

Practice first

It’s always a good idea to do a few practice passes to ensure you can complete the entire weld in a comfortable position. If you’re not in a comfortable position, it can result in an inconsistent weld.

Just remember that your filler metal choice and mode of transfer will determine what welding position you can use. If you need to weld overhead or out of position, be sure your filler metal is capable of that and then dial in your weld parameters to help optimize out-of-position welding. To learn more about the five basic types of weld joints, read this article.