Welding is an essential fabrication process used in the manufacturing and commercial construction industries to join multiple objects. As you may know, it involves heating the respective objects, thereby causing them to melt.
As the objects begin to cool, they fuse together to create a secure connection. While all welding processes are performed by melting the objects, there are two primary ways in which they are performed: forehand or backhand. So, what’s the difference between forehand and backhand welding?
What Is Forehand Welding?
Forehand welding is a welding technique that’s characterized by the application of the rod before the torch.
With forehand welding, the worker holds the torch at roughly a 30-degree angle from his or her right side. This allows the torch to point directly between the rod and the welding puddle.
When compared to backhand welding, forehand welding offers a superior level of penetration. The torch is able to heat hard, dense objects by penetrating through them.
The downside to forehand welding is that it tends to produce more splatter while also promoting an inconsistent arc.
What Is Backhand Welding?
Backhand welding is a welding technique in which the worker welds the objects from left to right. Also known as pull welding, it involves applying the torch before the rod itself.
Although there are exceptions, backhand welding is typically included at about a 15-degree angle on the worker’s right side. The worker is then able to add the filler metal from his left side.
Backhand welding offers several benefits, one of which is a consistent arc. Because of the position of the torch and filler rod, the worker is able to create an even and consistent arc.
In turn, this allows the worker to evenly distribute the filler metal. Backhand welding also creates less splatter than forehand welding, making it desirable among workers.
Forehand and Backhand Welding for Other Fabrication Processes
The main difference between forehand and backhand welding is the way in which the torch and rod are held.
Forehand welding involves holding and applying the torch before the rod, whereas backhand welding involves holding and applying the rod before the torch.
With names such as “forehand welding” and “backhand welding,” you may assume that are only used for welding. However, both of these techniques can be used for other fabrication processes, including brazing and soldering.
Brazing and soldering, of course, are unique fabrication processes because, unlike with welding, they don’t melt the objects intended to be joined. Regardless, forehand and backhand techniques can be used for all three fabrication processes.
Similarities between forehand welding and backhand welding
- Forehand and backhand welding techniques are associated with fusion welding processes (primarily gas welding, but the concept is equally applicable to most arc welding processes).
- Most of the arc welding and gas welding processes can be carried out either in forehand or in the backhand technique.
- Filler metal can be applied in both configurations.
- Flame or arc length remains within same range regardless of forehand or backhand strategy employed.
- Irrespective of welding technique, the joint quality depends predominantly on the capability of the welder.
Differences Between Forehand and Backhand Welding
Now let’s go through the differences between each of these welding techniques, and why they might matter to any given project you’re working on.
The angle of the torch.
In forehand welding, the angle of the electrode is pointed towards the direction of the weld progression. A weld moving left will hold the torch at an angle so the tip is further to the left than the main torch, and the filler rod is ahead of its direction of travel, to the left of the tip of the torch.
Conversely, in backhand welding, the same angle and configuration would be in place, except the direction of travel would be to the right. A good illustration of the difference is in this representation from minaprem.com.
Technically speaking, the forehand welding technique’s torch is held at an angle between 135 and 150 degrees – an obtuse angle – while in backhand welding, the torch is held at an acute angle of 30-45 degrees, relative to the feed vector. Again, this is easier to see in image or video than as described in text.
Position of the torch.
Relative to the weld bead, the forehand welding technique places the torch above the completed weld bead.
This can present a challenge in keeping the torch at an appropriate distance from the workpiece, as it can be harder to judge that distance when a still-hot weld beads beneath the torch.
Conversely, the backhand weld technique travels over the unfilled root gap. This makes it slightly easier to see the positioning of the torch, though if you have a beveled or u-grooved root gap, that can present challenges of its own.
Where filler is deposited, with forehand welding, the filler metal is applied ahead of the torch. The torch essentially melts the filler metal into the workpiece, melting all of it at once and leaving a molten pool behind to mix and solidify on its own.
With backhand welding, the filler metal is applied behind the torch, using not just the heat of the arc but the heat of the molten base metals to help melt and distribute the filler metal.
Effective pre-heating and post-heating.
With the push mode of welding, the angle of the torch technically has a small amount of preheating for the material directly in front of the torch. With backhand pull welding, there’s no such preheating.
However, this is a very minimal difference in arc welding and is much more applicable to similar forms of welding using oxyfuel torches or other direct heat application methods.
As you might imagine, the opposite is true of post-heating. The push method of welding does not reheat the materials.
Conversely, in backhanded welding, the residual heat does a sort of post-heating and annealing effect. Again, this is more applicable to flame-based welding rather than arc welding.
The balance between deposition and penetration.
Perhaps the biggest difference between forehand welding and backhand welding is the balance between two factors: the deposition rate of filler material and the penetration of heat to the workpieces.
Forehand welding, the push-mode form of welding, tends to allow for a faster feeding rate of filler material, which allows for a faster deposition rate for that filler material. This can allow for a fast weld across the length of a workpiece seam.
The trade-off to this faster deposition rate is that you don’t spend as much time in any one spot in the weld, which means you don’t have as much of a chance for deeper penetration.
If you go too slow, though, you deposit too much material and end up with an oversized and ineffective weld bead that will likely require a lot more cleanup.
When you invert these factors for backhand welding, you can see how they vary. Backhand welding has the option for slower travel speed without ramping up the deposition of the filler material. This allows for deeper and better penetration of heat into the weld.
However, because of the position of the filler rod, you don’t deposit as much material as quickly, so you can end up with shallow or too little filler added to the weld if you’re not careful.
Spatter and slag.
Another significant difference between forehand and backhand welding is the spatter, slag, and general cleanliness of the weld you create.
Unfortunately, forehand welding tends to have more spatter and dirtier welds, all else being equal. Conversely, backhand welding doesn’t produce as much slag and spatter.
Visibility.
One of the factors we mentioned above is worth repeating: because of the position of the torch and the weld pool, forehand welding tends to offer better visibility of the area in front of the torch.
It can be more difficult to see what’s under the torch in the weld pool itself, and since some issues can be diagnosed based on the color and behavior of the weld pool or its inclusions, this can be an issue.
On the flip side, with backhand welding, visibility is a bit worse for the actual point of welding, but the results of the weld are clearer.
Thickness viability.
Given the comparatively light penetration of forehand welding, it’s generally better used for joining up thinner plates or material that has been prepared to be thinner. It’s also possible to use this technique for multi-pass welding more easily.
Conversely, the deeper penetration of backhand welding means it’s better for joining slightly thicker materials.
Of course, for very thick or very thin materials, changing the position and direction of travel is generally not enough, and you will need to adjust other parameters, like the current you’re using.
Differences between forehand welding and backhand welding
| Forehand Welding | Backhand Welding |
| In forward welding, the flame or electrode is pointed towards the direction of weld progression. | In backward welding, the flame or electrode is pointed away from the direction of weld progression. |
| Here the torch is inclined at an obtuse angle (usually 135° – 150°) with the feed vector. | Here the torch is inclined at an acute angle (usually 30° – 45°) with the feed vector. |
| The torch is situated above the deposited weld bead (puddle). | The torch does not remain above the weld bead, rather it remains above the unfilled root gap. |
| Filler metal is applied ahead of the torch. | Filler metal is applied behind the torch. |
| Pre-heating of the base metals takes place automatically in the forehand technique. | No pre-heating occurs here. |
| No post-heating occurs here. | The backhand welding technique facilitates the post-heating of the deposited weld bead. |
| The weld joint is subjected to undesired residual stress. | Post-heating allows the joint to be continuously annealed which helps to relieve the residual stress. |
| Pre-heating offers a faster torch-feeding rate, which helps in improving productivity. | Torch feeding rate is usually slow due to a lack of pre-heating. |
| It increases the filler deposition rate but cannot fetch deeper penetration. | It assists in achieving deeper penetration, though the filler deposition rate is slow. |
| The tendency of spatter formation is more with the forehand technique. | The backhand welding technique creates comparatively less spatter. |
| This technique offers good visibility to the welder. | The weld zone has poor visibility. |
| It is preferred for joining thin plates (usually up to 3.0 mm without edge preparation). | It is preferred for joining thicker plates. |