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Arc force, sometimes called dig or arc control, changes how a stick welder responds when the electrode gets close to the workpiece. A higher setting increases welding current briefly during a near-short circuit. This helps prevent the rod from sticking, but it also produces a harsher arc, more spatter, and a deeper, less controlled puddle.
The correct setting depends on the electrode, joint, position, base metal, and welder. Arc force is not a substitute for correct amperage. Set the current first, then use arc force to fine-tune arc behavior.
What Arc Force Does
During normal stick welding, the electrode tip is held slightly above the molten pool. If the gap becomes too small, the arc nearly goes out. The welder detects the drop in voltage and adds current for a moment. That extra current can force the arc back open.
On a low arc-force setting, the arc feels softer and quieter. The puddle is easier to control, especially on thin steel, but the rod may stick more easily. On a high setting, the arc is more aggressive. It digs into the joint, helps maintain penetration, and is more tolerant of a tight arc length. The trade-off is increased spatter, undercut risk, and a greater chance of blowing through thin material.
Arc force only works within the limits of the machine and electrode. A welder with a basic fixed arc characteristic may provide little practical adjustment, while an inverter with a wide arc-control range may make a noticeable difference from one setting to the next.
Starting Settings by Electrode
Use the following as starting points, not fixed rules. The numbers are usually shown as a percentage, a numbered scale, or a low-to-high control. If your machine has a 0–10 dial, the approximate positions below are useful.
| Electrode | Typical current | Starting arc force | Useful adjustment |
|---|---|---|---|
| 6010 or 6011 | 70–130 A, depending on diameter | Medium-high, 6–8 out of 10 | Raise it for root gaps and dirty steel; lower it if the arc is too violent |
| 6013 | 60–125 A | Low-medium, 2–5 out of 10 | Use a softer setting for sheet and appearance; add force if the rod sticks |
| 7018 | 80–160 A | Low-medium, 2–4 out of 10 | Raise slightly for tight joints or vertical-up work; avoid excessive digging |
| Stainless electrodes | 50–110 A | Low, 1–3 out of 10 | Keep the arc calm to limit spatter and overheating |
Electrode diameter matters as much as type. A 3/32-inch rod generally needs less current and produces a smaller puddle than a 1/8-inch rod. Check the electrode package for the recommended amperage range and polarity before changing arc force. Many 6010 electrodes prefer direct current electrode positive, while some 6011 rods are used on AC or DC. 7018 rods are commonly run DCEP, but the package specification takes priority.
How to Set Arc Force for Common Electrodes
6010 and 6011
These fast-freeze electrodes are designed for digging into the joint and handling less-than-perfect steel. Start with medium-high arc force and a relatively tight arc. This is particularly helpful for root passes, open-root joints, repairs, and vertical work.
If the rod sticks every time you shorten the arc, increase the setting one step. If the puddle becomes excessively turbulent, the edges of the bead are undercut, or spatter is covering the surrounding plate, reduce it. A high setting can make a 6010 arc difficult to control on thin material.
6013
6013 electrodes have a smoother, more forgiving arc and are common for light fabrication and general repairs. They usually work best with low-to-medium arc force. Too much force defeats their soft operating character and can produce a wide, rough bead.
For thin steel, start near the low end and use a short arc without dragging the electrode aggressively. If the rod freezes when you pause at the edge of the joint, add a small amount of arc force or increase amperage slightly. Do not solve repeated sticking by turning the control fully up; excessive heat may burn through before the arc becomes manageable.
7018
7018 produces a smooth, fluid puddle and generally benefits from a softer arc. Start with low-to-medium arc force, a short arc, and steady travel. High arc force can create unnecessary spatter and a deep, narrow profile that is less suitable for controlled fill passes.
Increase arc force modestly for vertical-up welding, a poor fit-up, or a joint where the rod tends to stick as you manipulate the puddle. If the bead is cold at the toes, raising current may be more appropriate than raising arc force. Keep low-hydrogen electrodes dry according to the manufacturer’s instructions; arc-force adjustment will not correct moisture-related porosity or cracking.
A Practical Adjustment Method
1. Clean the joint and establish a good work clamp connection. Rust, paint, mill scale, and a poor ground can mimic an arc-force problem.
2. Choose the electrode and set amperage near the middle of its recommended range. Set the polarity specified on the package.
3. Start arc force in the middle for 6010 or 6011, and near the low-middle range for 6013 or 7018.
4. Weld a short bead on scrap of the same thickness. Keep the arc length consistent. For most electrodes, the gap should be about equal to the rod’s metal diameter, though 6010 and 6011 may be run slightly tighter.
5. If the rod sticks during normal manipulation, increase arc force one step. If the arc is harsh, the puddle digs too deeply, or spatter increases sharply, lower it one step.
6. Inspect the bead after it cools. Look for undercut, overlap, porosity, slag inclusions, and lack of fusion. Grind or wire-brush between passes; trapped slag can be mistaken for a setting problem.
When a Different Welder Helps
If you weld only occasional brackets, gates, or repairs with 6013 and 7018, an inexpensive inverter stick welder with basic arc-force adjustment may be enough. Spend more for adjustable arc force when you regularly use 6010, weld in vertical or overhead positions, work with inconsistent fit-up, or need predictable starts and arc recovery.
When shopping, compare the machine’s stated duty cycle at a real output, not only its maximum amperage. A welder advertised at 200 amps may run 200 amps for only a short period. For frequent stick work, look for a usable duty cycle around 40% or higher at the current you actually need. An inverter stick welder with adjustable arc force is often the best value for varied electrodes.
Also budget for an appropriate selection of stick electrodes, a sound work clamp, and a properly rated auto-darkening welding helmet. A better helmet and clean preparation usually improve results more than paying extra for a wider arc-force scale.