And because understanding this topic involves some sort of imagination to grasp the exact meaning of each case, I tried my best to accompany each explanation with a visual illustration ( photo or video ).
Preview what’s to come / table of contents.
- What is a welding position?
- Why should I know the welding positions?
- The Main Types of Welds
- Fillet weld
- Groove weld
- The main welding positions
- Flat Welding Position ( 1F or 1G )
- Horizontal Welding Position (2F Or 2G)
- Vertical Welding Position (3F Or 3G)
- Uphill ( or upward ) position
- Downhill position
- Overhead Welding Position (4F Or 4G)
- Pipe welding positions
- 1G pipe welding position
- 2G pipe welding position
- 5G pipe welding position
- 5G Uphill Position
- 5G Downhill Position
- 6G Pipe Welding Positions
- 6GR test position
- Welding positions according to ISO
What is a welding position?
Welding position, in simple words, describes the positional relation between the welding processor and the workpiece. In other words, it describes in which position the welding processor is facing the workpiece and welding.
Why should I know the welding positions?
It might come to mind the question, why should I even know the different types of welding positions? Why don’t I just weld in any position I like? Isn’t welding the same irrespective of the position I weld in?
Actually, It’s not that simple. Depending on your position, you may use different techniques, tools, materials ( such as the electrode type), and some other parameters ( such as the current ).
So, if you are able or qualified to weld in a certain position, you may not be able to weld in another.
For this reason, organizations like the American Welding Society ( AWS ) have defined the different welding positions and put a naming system to distinguish these positions.
With that, any welder can take a test for a specific position and become qualified to weld in it.
AWS is not the only organization to put standards and classifications for the welding positions.
The International Organization for Standardization ( ISO ) also has its own system for defining the different positions.
However, the idea is almost the same as the AWS, what differs is the coding system.
Before we move forward, just bear in mind that these positions ( such as 1F, 2G, 3G,..etc) we will talk about in this article are test positions. Meaning that these are discreetly defined positions for testing purposes.
The Main Types of Welds
There are two main types of welds
Fillet weld
This is the most common type of weld and it makes up about 70% to 80% of arc welding joints.
Fillet weld is when joining two pieces of metals that are perpendicular to each other. Thus it has a triangular cross-section.
Because it needs less preparation of the edges, it’s more cost-efficient. which explains one of the reasons for its popularity.
Groove weld
Groove weld involves an opening or a gap between the two pieces you want to join together.
Groove weld requires skilled welders to perform and it consumes more time to carry out.
The main welding positions
According to the American Welding Society ( AWS ), There are four main welding positions which are :
- Flat position
- Horizontal position
- Vertical position
- Overhead position
Depending on the weld type and the shape of the workpiece, the AWS has designated different codes for each scenario.
To make it more clear, let’s have a deeper look at the AWS naming system for the different cases of welding positions.
So, we have the number which serves to define the position of the welding.
The number (1) refers to the flat welding position, (2) for the horizontal position, (3) for the vertical position, and (4) for the overhead position.
And we have the letter, either F, which refers to the fillet weld, or G for groove weld.
Flat Welding Position ( 1F or 1G )
In this case, which some call the down-hand position, you will perform welding from the upper side of the joint.
In this position, the gravity force is your best friend and works for you!
This is why welders consider this position the easiest and the fastest to perform. And usually, beginners start their welding learning journey by welding in this position.
The molten metal tends to draw downwards into the joint, and that is exactly what you want.
1F is for fillet flat welding, while G is for groove flat welding.
Horizontal Welding Position (2F Or 2G)
Here is where things get harder and gravity is not your best friend anymore!
This position is not as easy as the flat position and requires more skills.
The Axis of the weld is approximately horizontal. In fact, even in the flat position, the weld axis is horizontal, but what differs is the weld face direction.
For the flat position, the weld face lies along almost a horizontal plane.
For the fillet weld (2F), the two pieces of metal meet at an angle of 90-degree and one of the surfaces is almost on a horizontal plane. while the other is almost vertical.
For this position, the welder will be often holding the torch at an angle of 45-degree.
For groove weld ( 2G ), the weld face is along almost a vertical plane and the surfaces of the two metal pieces are approximately on a vertical plane.
Vertical Welding Position (3F Or 3G)
What differentiates this position from all other positions is that the weld axis is almost vertical.
Here, Gravity will force the molten metal to get downward causing it to deposit and pile up.
To overcome the impact of the gravity force and avoid metal piling up, the welder should either weld in an uphill or downhill position. Also, directing the flame to point upwards with an angle of 45-degree to the weld axis will help with this issue.
Uphill ( or upward ) position
The welder performs uphill welding by welding from the down top with an upward progression.
Using the metal from the bottom parts of the workpiece while holding the flame with a 45-degree upwards to the plate will help with controlling the molten metal.
Welding this way can form a sort of like a shelf for the molten puddle to stay on for an extended time. This gives it the opportunity to have greater penetration
Downhill position
Welders carry out this position by welding from the top down with a downward progression. You could say it’s the opposite of the uphill position in terms of travel direction.
But, it’s the same when it comes to the way of pointing the flame and holding the torch.
A question might arise, Should I weld downhill or uphill? Which one is better?
Well, the answer to this question belongs to the “ it depends “ type of answer.
Uphill welding can result in stronger welds, but, it consumes a longer time. Furthermore, due to the longer time it takes, the likelihood of burn-through is higher.
The downhill position provides less penetration so it is adequate for welding thinner steels where there is no need for higher penetration.
Downhill has a faster travel speed, which results in cooler temperatures that in turn results in less probability for the formation of burn-through
So, as a general rule, for thicker sheet metal, it’s better to go for uphill welding, whereas for thinner sheet metal, downhill is adequate.
Overhead Welding Position (4F Or 4G)
Here is where the gravity force is your real enemy because you will be working against it.
Overhead welding, as the name suggests, is welding while the workpiece is over the head of the welding processor. in other words, the welder is performing welding from the underside of the joint.
One major concern with this position is that it could cause the formation of a higher crown. That happens due to the tendency of the molten metal from the plate to drip or sag. This usually happens with beginners or inexperienced welders.
As for skilled welders they use some techniques to avoid the occurrence of a high crown, one of which is keeping the puddle of molten metal small in size.
Another description you may hear for the vertical and overhead positions is that they are ” out of position ” positions. Both positions are inherently more difficult than other positions. In the overhead position, gravity is not your only problem. You may also frequently find yourself needing to adopt an awkward posture.
So, because of Gravity, you will have to weld in a colder and slower manner resulting in less quality weld either from the aesthetical or structural perspective.
Sure, needless to say, 4F stands for fillet welding and 4G for groove welding.
Pipe welding positions
Because the shape of the pipe is not the same as the plate, welding pipes require some other positions than plate welding in some cases.
When it comes to pipe welding, there are 4 main welding positions which are :
1G Pipe Welding Position
As in 1G and 1F in plate welding, 1G here is the easiest welding position for pipes. In this case, the pipe is lying down in a horizontal position and it can rotate about its central horizontal axis. The welder performs welding from the top side of the joint while slowly rotating the pipe about its axis.
Because the pipe rotates, the welder will not have to change his position. This explains why this position is the easiest and the most basic for pipes welding.
2G Pipe Welding Position
In this position, you align the pipe vertically and it can either have the ability to rotate about its vertical axis or it can be fixed. The welding travel direction is horizontal.
5G pipe welding position
5G position, Also called the multiple welding position, is the same as the 1G position except that the pipe is fixed.
Because the pipe can not rotate, the welder will have to weld in several positions within this position.
The welder will either begin welding from the underside and move upward or weld from the above side and move downward.
5G Uphill Position
In this case, the welding processor begins welding from the downside. the pipe will be above his/her head and the travel direction of welding is almost horizontal. That is an overhead position. As he/she moves forward, the curvature of the pipe will force him/her to gradually change the welding travel direction until the welder becomes facing the pipe in front of him/her.
The travel direction will become almost vertical, and that is a vertical Position. Now, the welder will keep moving upward until he/she faces the joint from above and weld in almost a horizontal travel direction. And that is, you name it, a flat welding position.
So, the welder has performed the job in 3 different positions within this position.
The welder will do the same procedures from the other side.
5G Downhill Position
In this vertical-downward position, the welder begins from the top side and moves downward passing through 3 welding positions starting from the flat position to vertical and eventually the overhead position.
6G Pipe Welding Positions
So, you think 5G pipe welding is difficult because the pipe is fixed and therefore you need to weld in multiple positions and assume different postures to perform welding? right?
But, what if we make the pipe not lying down horizontally( like in 5G ) nor standing vertically upright, but rather it’s inclined at a 45-degree angle? That is exactly the 6G position.
6G position, obviously, is the hardest and most challenging position. Welders can perform it either uphill or downhill.
6GR test position
It’s another form of the 6G position with the addition of a restriction ring near the joint making welding a more challenging task. So, the letter R here stands for ‘restricted’.
So, it’s basically, the same as 6G with additional difficulty.
Welding positions according to ISO
As mentioned earlier, the concept is almost the same as in AWS. what differs is the approach each organization took to name each position.
Thus, the table below shows each position according to the AWS and what corresponds to it in the ISO standard.
| AWS | ISO |
|---|---|
| 1G / 1F | PA |
| 2F | PB |
| 2G | PC |
| 3G Uphill | PF |
| 3G Downhill | PG |
| 4F | PD |
| 4G | PE |
| 5G Uphill | PH |
| 5G Downhill | PJ |
| 6G Uphill | H-L045 |
| 6G Downhill | J-L045 |
