Which Welding Rod? Picking Electrodes for Mild Steel vs Stainless
The job looks the same from across the shop — strike an arc, lay a bead — so it's tempting to reach for whatever stick electrode is already in the holder. Then the weld on the stainless bracket rusts in a month, or the structural joint cracks under load, and the real lesson lands: the rod is not a detail, it's half the weld. Picking the right electrode for the base metal, the load, and the position is what separates a bead that holds for twenty years from one that fails the first time it's tested.
This guide is for the welder, fabricator, or workshop owner choosing stick (SMAW) electrodes for the two materials that fill most Thai shops: mild (carbon) steel and stainless steel. We'll cover how to read an electrode code, which rods suit which job, the low-hydrogen rule that prevents cracking, and when brazing beats welding altogether.
Reading the electrode code
Every stick electrode carries a classification that tells you exactly what it is. For carbon-steel rods the AWS code looks like E6013 or E7018 , and each digit means something:
- E — electrode.
- First two digits — minimum tensile strength in thousands of psi. E60xx = 60,000 psi; E70xx = 70,000 psi (roughly 490 and 570 MPa).
- Third digit — welding positions the rod can run (1 = all positions).
- Fourth digit — the flux coating type and current. This sets how the rod runs and whether it's low-hydrogen.
So an E6013 is a 60 ksi, all-position, rutile-coated rod — smooth, forgiving, easy to strike, the classic general-purpose electrode. An E7018 is a 70 ksi, all-position, low-hydrogen rod with iron-powder flux — stronger, more ductile, and the choice for anything structural. Stainless electrodes use a different code based on the alloy, like E308L-16 or E309L-16 , where the number (308, 309, 316) matches the stainless grade and the "L" means low-carbon.
Mild steel: E6013 vs E7018
For carbon steel, almost everything comes down to a choice between a general rutile rod and a low-hydrogen rod.
| Electrode | Best for | Why |
|---|---|---|
| E6013 (rutile) | Sheet, general fabrication, light brackets, repairs | Easy to strike and restart, smooth arc, tidy bead, tolerant of less-than-perfect prep and rusty steel |
| E7018 (low-hydrogen) | Structural steel, thick sections, load-bearing and dynamic joints | Higher strength and toughness, very low weld-metal hydrogen, resists cracking in restrained or thick joints |
In Thai shops the YAWATA FT-51 rutile electrode (to TIS 49-2528) is the everyday mild-steel rod for structural and general work, while YAWATA L-55 is the low-hydrogen rod for joints that must carry real load, with tensile strength to around 490 N/mm². You can see both on theYAWATA welding electrode page . The rule of thumb: if the joint is decorative, light, or non-critical, a rutile rod is faster and easier; if it carries weight, fatigue, or shock, move to low-hydrogen.
Match the current and polarity to the rod, too. Most rutile rods run on AC or DC either polarity; most low-hydrogen rods prefer DC electrode-positive (DC+). Set amperage to the electrode diameter — very roughly 30–40 A per millimetre of rod diameter — then fine-tune by how the arc sounds and how the bead lies. Too little current and the rod sticks and piles up; too much and it burns through and spatters.
Stainless steel: match the grade, keep the carbon low
Stainless is where the wrong rod quietly ruins the job, because a bad stainless weld often looks fine and only rusts later. The principle is to match the filler to the base alloy and keep carbon low:
| Base metal | Electrode | Notes |
|---|---|---|
| 304 / 304L stainless | E308L-16 | The standard match for the most common stainless; "L" resists weld-decay corrosion |
| 316 / 316L stainless | E316L-16 | Adds molybdenum for marine, chemical, and chloride environments |
| Stainless welded to mild steel | E309L-16 | Dissimilar-metal rod that bridges the two without cracking |
The "L" (low-carbon) grades matter more than they look. When stainless is heated in the weld zone, ordinary higher-carbon filler can let chromium and carbon combine at the grain boundaries (sensitisation), stripping the corrosion resistance exactly where you welded — so the joint rusts first. Low-carbon 308L/316L fillers avoid this. Use stainless rods on DC+ where possible, run them slightly cooler and faster than carbon steel to limit heat input and distortion, and never grind stainless with a disc that has touched carbon steel — embedded iron particles will bloom into rust spots on the stainless surface.
When to braze instead of weld
Not every joint should be arc-welded. Brazing — joining with a filler that melts well below the base metal, drawn into the joint by capillary action — is the right answer for several jobs a stick welder struggles with: copper pipe and fittings, carbide tips onto steel tool bodies, thin or dissimilar metals, and anywhere you need a clean, leak-tight joint without melting the parts.
Silver brazing alloys flow at 630–760 °C, far below the melting point of steel or copper, so they join without distorting or burning thin parts, and the silver content gives a strong, ductile, conductive joint. A silver brazing rod, plate and flux set from BrazeTec (to ISO 17672) covers copper, brass, stainless and carbide work; the flux is essential because it strips surface oxide and lets the alloy wet and flow into the joint. Heat the parts until they melt the rod — never melt the rod directly with the flame — and the alloy is pulled into the gap on its own.
BOWMAP Industry & Tooling, a Samut Prakan supplier of Japanese-quality industrial tools, stocks YAWATA mild-steel and low-hydrogen electrodes alongside stainless rods, silver brazing alloys and fluxes, so a workshop can match the consumable to the metal and the load rather than welding everything with one rod.
FAQ
Q1. What's the difference between E6013 and E7018? E6013 is a 60 ksi general-purpose rutile rod — easy to strike, smooth, forgiving on sheet, brackets and repairs. E7018 is a 70 ksi low-hydrogen rod that is stronger, tougher, and resists cracking, which makes it the choice for structural and load-bearing steel. Use E6013 for light or non-critical work and E7018 (kept dry) for anything that carries real load.
Q2. Which rod do I use to weld 304 stainless? Use an E308L-16 electrode — it matches 304/304L and the low-carbon "L" grade prevents the chromium-carbide sensitisation that would otherwise let the weld zone rust. For 316 stainless use E316L; to weld stainless onto mild steel, use E309L, which is formulated for dissimilar-metal joints.
Q3. Why must low-hydrogen rods be kept dry? Low-hydrogen electrodes like E7018 (and YAWATA L-55) absorb moisture from the air into their flux, and that moisture becomes hydrogen in the weld, which causes brittle cracking in thick or restrained joints. Store them in a sealed container or a heated rod oven, and re-bake damp rods per the maker's instructions before welding anything critical.
Q4. Can I weld copper or carbide with a normal stick electrode? No — those are brazing jobs, not arc-welding jobs. Copper pipe, carbide tips on tool bodies, and thin or dissimilar metals are joined with a silver brazing alloy and flux, which flows at 630–760 °C and is drawn into the joint by capillary action without melting the base parts. A stick arc would simply overheat and ruin them.
