Stick current starts from rod diameter, not from a guess on the dial. This calculator uses the shop rule of about 1 amp per 0.001 in of electrode, then opens a ±15% window to hunt in. Optional plate thickness is a pairing note only — it does not change the number. Starting point, not a welding procedure.
Stick current starts from rod diameter, not from a guess on the dial.
Use it as the starting point when setting up for an electrode you have not run recently. Pick the rod diameter and the page gives the rule-of-thumb current and a range; then run a test bead on scrap of the same thickness and position and adjust. The electrode maker’s label has the final say.
Covered electrodes carry current in a steel core. A long-used shop rule sizes that current from the core diameter: about one ampere per thousandth of an inch. A 1/8 in rod is 0.125 in, so the midpoint is 125 A. The page then reports a window 15% below and 15% above that midpoint — room to walk the puddle without treating the dial as a specification.
Imid = din × 1000
Ilow = Imid × 0.85 · Ihigh = Imid × 1.15
Millimetres first become inches: din = dmm / 25.4
Displayed amps are those three values rounded to the nearest ampere. The arithmetic underneath is not rounded until that last step. Thickness, when you type it, is a pairing comment only. A rod that is fatter than the plate is a burn-through warning. A plate many times thicker than the rod is a multi-pass warning. Neither one rewrites Imid.
This is not AWS A5.1, not the carton, and not a WPS. Fast-freeze E6010 often wants the lower half of a generic window. Low-hydrogen E7018 on flat work often sits on or a little above the midpoint. Polarity, position, joint, machine slope, and the puddle decide the real setting. Strike a coupon.
Manufacturer windows below are Lincoln Electric typical operating procedures, DC+ (preferred polarity listed first on those sheets): Fleetweld 5P for E6010, Excalibur 7018 MR for E7018. A 1/8 in 7018 is listed 90–160 A DC+; the middle of that window is 125 A, which is also this page’s shop-rule midpoint. Many welders land 110–150 A on flat 1/8 in 7018. Other brands print different numbers. Read the tube you opened.
| Diameter | E6010 DC+ | E7018 DC+ | Shop rule ±15% |
|---|---|---|---|
| 3/32 in (2.4 mm) | 40–80 A | 70–110 A | 94 A · 80–108 A |
| 1/8 in (3.2 mm) | 70–130 A | 90–160 A | 125 A · 106–144 A |
| 5/32 in (4.0 mm) | 90–165 A | 130–210 A | 156 A · 133–180 A |
| 3/16 in (4.8 mm) | 140–225 A | 180–300 A | 188 A · 159–216 A |
E6010 of a given diameter usually runs cooler than E7018. The shop-rule window for 1/8 in (106–144 A) sits inside Lincoln’s 7018 listing and a little high for 6010’s 70–130 A. Start 6010 lower. Vertical-up and overhead typically want the bottom of whatever window you are in — drop on the coupon, do not invent a second formula.
| Electrode | Imid = d × 1000 | ±15% (rounded) |
|---|---|---|
| 1/8 in (0.125) | 125 A | 106–144 A |
| 3/32 in (0.09375) | 93.75 A → 94 A | 80–108 A |
| 5/32 in (0.15625) | 156.25 A → 156 A | 133–180 A |
| 3.2 mm (nominal 1/8) | 125.98 A → 126 A | 107–145 A |
Those four rows use the same math as the calculator (I = d_in × 1000, millimetres ÷ 25.4, then round half-up to whole amps). The default example is the first row: 1/8 in → 125 A midpoint. Metric 3.2 mm is the labeled stand-in for 1/8 in, not 0.125 × 25.4 = 3.175 mm, so it comes out one amp higher. Use the number printed on the rod.
As a midpoint, yes: 0.125 × 1000 = 125. That is the usual shop check and the default on this page. It is also the middle of Lincoln’s 90–160 A DC+ window for 1/8 in Excalibur 7018 MR. It is not automatically the number for 6010, vertical-up, sheet, or a cold machine. Open at 125, then move 5–10 A at a time until the puddle wets without undercut or a pile of spatter.
Rod coating, polarity, joint, position, and how long the rod has been out of the oven all move the sweet spot. A hard single number pretends those are fixed. ±15% around the shop rule is a hunt window, not a tolerance on a drawing. If the puddle is sluggish, go up. If it is blown through or undercutting, go down. Stay inside the carton range when that range is tighter than this window.
Not on this calculator. Current is sized to the electrode. Thickness tells you whether that electrode is a sane choice: a 1/8 in rod on 16-gauge will blow holes at 125 A; a 1/8 in rod on 3/4 in plate will not fill the joint in one pass no matter where you set the dial. Enter thickness if you want that note. Leave it blank if you already picked the rod.
The big figure is the generic shop rule. Use the chart for the class in the oven. 6010 is a deep-penetrating cellulosic rod, DC+ on Lincoln Fleetweld 5P, and it likes the lower half of a given diameter. 7018 is low-hydrogen, DC+ preferred, and on flat fillets a 1/8 in rod often lives at 110–150 A. AC, when the carton allows it, usually wants a little more current than DC+. Keep 7018 dry.
No. A WPS is a qualified document: process, filler, position, polarity, amperage range, travel, preheat, and the code that owns the joint. This page is a starting guess from rod diameter so you can light a coupon without staring at a blank dial. It does not qualify a welder, a machine, or a joint. If the work needs a WPS, get one.
Use the stamp on the rod. US fractional sizes (3/32, 1/8, 5/32) are exact inch fractions. Metric labels (2.4, 3.2, 4.0 mm) are the usual millimetre stand-ins, not a converted 0.125 in. Mixing a 1/8 typed as 1.8 with millimetre units will invent a monster rod. The result is always in amperes.