Stick Electrode Guide: E6010, E6011, E7018 & Filler Selection

Decoding the AWS A5.1 Classification: What EXXYZ Actually Means

Every carbon-steel stick electrode carries an AWS A5.1 (or A5.5 for low-alloy) designation printed on the flux near the grip end. The code looks cryptic until you break it into four fields: the E prefix, a two- or three-digit tensile figure, a position digit, and a coating/current digit. Reading it correctly tells you the minimum tensile strength of the deposited weld metal, what positions the rod is designed to run, the coating chemistry, and the required polarity before you ever strike an arc.

In E7018, the 'E' means electrode. The first two digits, '70', mean 70,000 psi minimum tensile strength of the as-welded deposit. The third digit, '1', means all positions (flat, horizontal, vertical, overhead). The final digit, '8', identifies the coating as iron-powder, low-hydrogen and specifies the usable current. For four-digit numbers like E11018, the first three digits are the tensile figure (110,000 psi).

The position digit is straightforward: 1 = all positions, 2 = flat and horizontal fillet only, 4 = flat, horizontal, overhead and vertical-down. The last-two-digits pair (the position digit combined with the coating digit) is what really drives operating behavior, because the coating digit encodes both flux type and polarity.

• E (prefix): Denotes a filler-metal electrode covered by an AWS specification.
• First digits (60/70/80/etc.): Minimum tensile strength in ksi. E60xx = 60,000 psi, E70xx = 70,000 psi.
• Third-from-last digit (position): 1 = all positions; 2 = flat and horizontal only; 4 = includes vertical-down.
• Last digit (coating/current): 0/1 = cellulosic fast-freeze (DCEP); 3 = rutile fill-freeze; 8 = low-hydrogen iron powder (DCEP/AC).
• Optional suffix (e.g. -1, H4R, H8): Improved toughness (-1), moisture-resistant coating (R), and diffusible-hydrogen limits (H4 = 4 mL/100g max).

Fast-Freeze, Fill-Freeze, and Low-Hydrogen: The Three Families

Nearly every carbon-steel stick electrode falls into one of three operational families defined by how the puddle solidifies and how the flux is formulated. Understanding these three behaviors matters more day-to-day than memorizing every classification number, because it dictates joint fit-up tolerance, cleanliness requirements, and mechanical properties.

Fast-freeze electrodes (E6010, E6011) use a high-cellulose coating that produces a deep, digging arc and a fast-solidifying puddle. That combination bites through mill scale, rust, paint, and poor fit-up, and it holds a puddle out of position, which is why pipeliners run E6010 for open-root passes. The tradeoff is a violent arc, more spatter, and a deposit with higher diffusible hydrogen, so it is not used where cracking risk is high.

Fill-freeze electrodes (E6012, E6013, E7014) use rutile (titania) coatings that give a soft, quiet arc, moderate penetration, and easy slag removal. E6013 is the classic light-gauge and general-purpose maintenance rod; E7014 adds iron powder for higher deposition. These are forgiving for beginners and sheet metal but are not intended for critical, high-restraint joints.

Low-hydrogen electrodes (E7018, E7016, E7028) use a basic, iron-powder coating engineered to hold diffusible hydrogen very low. Low hydrogen means low risk of underbead and hydrogen-assisted (cold) cracking, which is why structural steel work under AWS D1.1, pressure piping, and any medium-to-high carbon or high-restraint base metal calls for 7018. The catch is that the coating readily absorbs atmospheric moisture, so storage discipline is mandatory.

E6010 vs E6011: Cellulosic Root Rods and Polarity Reality

E6010 and E6011 are close cousins that behave almost identically, but the difference matters at the machine. E6010 runs on DCEP (direct current electrode positive, or 'reverse polarity') only. Its high-cellulose sodium coating produces a tight, forceful, deep-penetrating arc ideal for open-root passes on pipe, where you need the arc to dig to the back side and produce a clean, uniform reinforcement. It is the pipeliner's standard for 5G and 6G root work and runs beautifully vertical-up or vertical-down.

E6011 uses a high-cellulose potassium coating that stabilizes the arc on alternating current, so it runs on AC as well as DCEP. That makes it the go-to fast-freeze rod for older engine drives and inexpensive AC-only transformer welders ('buzzboxes') that cannot run 6010. On AC the arc is a touch softer and penetration is marginally less than 6010 on DC, but it still digs through rust, oil, galvanizing, and questionable fit-up better than any rutile rod.

Both deposit 60,000 psi weld metal and both are all-position (the '1'). Neither is low-hydrogen: cellulosic rods intentionally rely on hydrogen from the coating to shield and dig, so they run 30-50 mL/100g of diffusible hydrogen. That is fine for mild steel and root passes that get burned out or reheated by subsequent low-hydrogen fill and cap passes, but do not use them as the finished weld on hardenable or high-restraint steel.

Practical technique note: cellulosic rods are run with a tight arc and often a whip-and-pause or slight drag motion. They are not stored in ovens; in fact, over-drying a 6010 degrades its running characteristics. Keep them at room temperature in a sealed container and they will run for years.

• 6010 = DC only: If your welder is AC-only, you physically cannot run 6010; reach for 6011 instead.
• 6011 = AC or DC: The universal fast-freeze rod for farm, ranch, and field repair on any machine.
• Do not oven-dry cellulosics: They need coating moisture to run correctly; store at room temperature, sealed.
• Root-pass discipline: On pipe, follow the 6010 root with 7018 fill/cap to get low-hydrogen final properties.

E7018 Moisture Control, Rod Ovens, and Reconditioning

E7018 is the most-specified structural electrode in the country, and it is also the most abused. Its low-hydrogen basic coating is hygroscopic, meaning it pulls moisture straight out of the air. Absorbed moisture breaks down in the arc into hydrogen, which diffuses into the weld and heat-affected zone and causes hydrogen-assisted cracking, often hours after the weld cools. On high-strength or high-restraint steel, a wet 7018 is a crack waiting to happen.

Standard (non-'R') E7018 must be kept dry. AWS D1.1 and most manufacturers require that once the hermetically sealed can is opened, electrodes go into a holding oven at 250-300 deg F (120-150 deg C). Atmospheric exposure is limited by code: for standard low-hydrogen electrodes the practical exposure limit is typically about 4 hours before they must be reconditioned. Moisture-resistant 'R' rods (E7018-1 H4R) tolerate up to roughly 9 hours of exposure, which is why field crews prefer them.

Reconditioning is not the same as holding. If electrodes have been exposed beyond their limit or the coating has clearly absorbed moisture, they must be rebaked, typically at 500-800 deg F (260-425 deg C) for one to two hours per the manufacturer's data sheet, then transferred to a 250-300 deg F holding oven. Never rebake cellulosic (6010/6011) rods and never rebake a given low-hydrogen rod more than the manufacturer allows, as excessive rebaking burns off the alloying and stabilizing agents in the flux.

Equipment-wise, a distributor will steer you to the right oven for the scale of your work. A 10 lb portable rod caddy runs $80-$180 and holds one operator's daily rods on a jobsite. A benchtop holding oven (50-100 lb) runs $250-$600. A rebake oven with adjustable high-temperature control and a thermostat runs $700-$2,500. On a jobsite, individual welders carry electrodes in insulated 'rod pigs' or portable ovens wired to the machine.

A quick field tell: a properly dry 7018 runs smooth with a tight, quiet arc and leaves easily-peeling slag. A moisture-loaded rod is noisy, sputters, throws more spatter, and can leave visible porosity and fine surface cracks. If in doubt on code work, rebake or open a fresh sealed can.

• Holding temp: 250-300 deg F (120-150 deg C) for opened low-hydrogen electrodes.
• Exposure limit: ~4 hrs for standard 7018; ~9 hrs for moisture-resistant 7018-1 H4R.
• Rebake temp: 500-800 deg F (260-425 deg C), 1-2 hrs, per manufacturer, then move to holding oven.
• H4 designation: Guarantees 4 mL or less diffusible hydrogen per 100 g of deposited metal when handled correctly.

Matching the Electrode to Base Metal Strength

The governing rule for structural and pressure work is undermatching versus overmatching the base metal tensile strength. For most carbon steel, you match the electrode's minimum tensile to the base metal's specified minimum. ASTM A36 structural steel has a 58,000-80,000 psi tensile and 36 ksi yield, so a 70 ksi filler (E70xx) is the standard match and the D1.1 prequalified choice. E60xx is generally reserved for lighter, non-critical mild steel.

As base metals climb the strength ladder, you step up the filler. A992 (modern wide-flange beam steel, 50 ksi yield) is welded with E70xx or E71T wire. A572 Grade 50 also pairs with 70 ksi filler. When you get into quenched-and-tempered high-strength steels or higher-yield plate, you move to E80xx, E90xx, E100xx, or E110xx low-alloy electrodes classified under AWS A5.5, and preheat and hydrogen control become non-negotiable.

Dissimilar-strength joints follow the weaker member: a joint between two different steels is generally welded to match the lower-strength base metal, because the weld only needs to develop that member's strength. For dissimilar metals such as joining carbon steel to stainless, you leave the A5.1 carbon world entirely and reach for an austenitic filler like E309/309L, which tolerates the dilution and carbon migration at the interface.

Toughness matters as much as tensile on anything seeing dynamic or low-temperature service. The A5.1 suffix '-1' (as in E7018-1) guarantees improved low-temperature Charpy V-notch impact toughness (typically 20 ft-lb at -50 deg F). For seismic and demand-critical welds under AWS D1.8, filler metals must meet specified CVN toughness, so read the WPS and the mill certs, not just the tensile number.

Sizing, Amperage, and Buying by the Pound

Electrode diameter is chosen by material thickness, joint position, and available machine amperage. A rough rule for flat position on carbon steel is about 1 amp per 0.001 in of electrode diameter, so a 1/8 in (0.125 in) rod centers around 90-140 A depending on classification. Move out of position (vertical, overhead) and you drop to the low end of the range and often step down a diameter to keep the puddle controllable.

Common diameters are 3/32 in (light sheet, low-amp machines, out-of-position), 1/8 in (the everyday workhorse), and 5/32 in (heavy plate, flat and horizontal, high deposition). A 5/32 in 7018 wants roughly 125-220 A; a 3/32 in wants roughly 70-110 A. Undersizing wastes time; oversizing burns through thin material and destroys out-of-position control.

Stick electrodes are sold by weight, most often in sealed 10 lb and 50 lb cans or cartons, and price varies sharply by classification and package. As a national ballpark from distributors and suppliers across the US, general-purpose 6010/6011/6013 runs about $3.50-$6.50 per lb, standard 7018 about $4.00-$7.50 per lb, and moisture-resistant 7018-1 H4R a bit more. Low-alloy rods (8018, 9018, 11018) and stainless (309/316) run $9-$30+ per lb. Buying full 50 lb cartons versus small 1-5 lb tubes typically cuts the per-pound cost by 20-40 percent.

Deposition efficiency is the number that actually controls your cost per foot of weld. Stick sits around 60-70 percent efficient once you subtract the stub loss (you throw away the last 2 in), slag, and spatter. That is why high-volume shops with good fit-up migrate to E7024 drag rods or leave stick for wire processes. When you compare a bid on rod cost alone, factor in that roughly a third of the electrode weight never ends up in the joint.

A distributor's practical buying tips: match your can size to how fast you will use it (a shop that opens a 50 lb can of 7018 and burns it in a week keeps it dry easily; a hobbyist should buy 7018 in small vacuum-sealed packs), always confirm the polarity your machine supports before ordering 6010, and keep a moisture-resistant 7018-1 H4R on the truck for fieldwork where oven access is limited.

• 1 amp per mil rule: Roughly 1 A per 0.001 in of diameter in flat position; drop 10-15% out of position.
• Stub loss: Discard the last ~2 in; it is a major reason stick efficiency lands near 65%.
• Buy the right can size: Full 50 lb cartons cut per-pound cost 20-40%, but only if you keep them dry and use them.
• Package for the job: Small vacuum-sealed 7018 packs protect infrequent users from moisture pickup.

Frequently Asked Questions