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

Understanding the four basic welding positions can help you chose the right filler metal and welding process for whatever project or job you’re tackling. 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?

Fillet and groove welds are performed 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) or on filler metal data sheets, which use them to call out the positional capabilities of specific filler metals. 

The filler metal you select, along with the welding process and transfer mode being used, dictate which position you can weld in. Regarding filler metal selection, some are designed to be used in all positions, while others are restricted to flat and horizontal welding only. The filler metal type will include a designation that denotes in what positions it can be used in. For example, there can be a flux-cored electrode 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: 

• TIG welding can be done in all positions.
• Short-circuit MIG can be done in all positions.  
• Spray transfer MIG is recommended 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 in the flat position because there is no worry about the puddle becoming too fluid and gravity pulling it out of the joint. 

Any welding process can be used 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 a slag during welding so you may want to use 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 because 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 make sure the heat is focused where the two pieces come together.  

Be careful not to run too hot in horizontal welds since a puddle that’s too fluid can be the victim of gravity. Tweak your weld parameters to make sure the puddle doesn’t get too hot or too fluid. 

All of the welding processes can also be used in the horizontal position. 

Vertical welding position

Vertical welds can be done 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. This welding position may be required when you’re working on a large weldment that cannot be easily moved 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 that are ideal for flat and horizontal welds on a vertical weld, it likely won’t produce a very good weld.

Adjust the weld parameters to achieve the best results in vertical welds. Use a reduced wire feed speed and voltage to make sure the puddle does not get too fluid and falls or sags 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. 

A 90-degree travel angle is typically recommended for a 3G weld, while a 45-degree angle is recommended 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. There are several common techniques for this puddle manipulation — including a zigzag motion, an upside-down T or repeated triangles stacked on top of each other — that can be used 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. It’s good to 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 or 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. The parameters should also be dialed back 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. 

One of the biggest factors to think about when welding in the overhead position is that the 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. 

Understanding welding positions

Whichever weld position you’re using, it’s always a good idea to do a few practice passes prior to performing the weld to make sure you can complete the entire length of the 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.