Welding current by electrode size

The starting point for stick welding is roughly 35 amps per millimetre of electrode diameter. A 3.2 mm rod runs around 110 amps, a 4.0 mm rod around 140. Set it too low and the rod sticks and the bead piles up on the surface; set it too high and the rod burns through the plate, undercuts the toes, and the coating glows red before you reach the end of the rod.

Which electrode for which job

• E6013 — the general purpose rutile rod. Easy to strike, smooth bead, slag lifts off cleanly. Sheet metal, gates, grilles, general fabrication. Runs on AC or DC.
• E6011 — cellulosic with deep penetration, and it runs on an AC transformer. The rod for dirty, rusty or painted steel and for site repair work. E6010 is the DC-only equivalent used for pipe roots.
• E7018 — low hydrogen, high strength, iron powder. Structural steel, pressure work, thick and restrained joints, anything that must not crack. Must be kept dry.
• E308L-16 — for welding 304 and 304L stainless to itself. E309L-16 joins stainless to carbon steel.
• E312-16 — high alloy, for unknown or difficult steels, spring steel, tool steel repair and high-strength tacking.
• ENiFe-CI — nickel-iron for cast iron repairs that still need to be machinable.

MIG wire size, current and voltage

Mild steel needs roughly 40 amps per millimetre of thickness for a single-pass fillet. Set the current first, then adjust voltage until the arc makes a steady crackle rather than a pop or a hiss. Stick-out of about 10 mm for short circuit, 15 to 20 mm for spray.

TIG tungsten size and colour code

Recommended filter lens shade

Shade numbers follow EN 169 as a guide. Choose the darkest shade through which you can still clearly see the weld pool — if you cannot see the puddle you cannot control it — but never go below the minimum for the current you are running.

Storing welding rods in a humid climate

This matters more in Malaysia than in almost any other market. At 80 to 90 per cent relative humidity, low-hydrogen electrodes left in an open packet on the bench pick up enough moisture in a single afternoon to cause hydrogen cracking — cracks that appear hours or even days after the job is finished, long after the welder has gone home.

The four-hour rule. Once a packet of low-hydrogen rod is opened, treat four hours of shop-floor exposure as the limit before re-drying — and much less than that in the rain, or in an air-conditioned room where condensation forms on cold steel. A damp rod spatters more than usual, the arc sounds harsh, the coating cracks or flakes, and the slag is hard to remove.

Frequently asked questions

What amperage should I use for a 3.2 mm welding rod?

Around 90 to 140 amps for E6013 and 110 to 160 amps for E7018. The general rule is about 35 amps per millimetre of electrode diameter, then adjust based on how the arc sounds and how the bead is running. Drop the current by 10 to 15 per cent for vertical and overhead work.

What is the difference between E6013 and E7018?

E6013 is a rutile general purpose rod — easy to strike, forgiving, and fine for gates, brackets and light fabrication. E7018 is a low-hydrogen rod with higher strength, used for structural steel, pressure work and thick or restrained joints. E7018 gives a stronger, crack-resistant weld, but it must be kept dry in a holding oven or its main advantage is lost.

What colour tungsten should I use?

Blue, 2% lanthanated, if you only want to stock one type. It works on AC and DC, so it handles steel, stainless and aluminium, starts easily and carries no radioactivity concern. Red thoriated is the traditional DC choice for steel but its grinding dust is mildly radioactive. Green pure tungsten is for AC aluminium on older transformer machines.

How do I set MIG voltage and wire speed?

Set the current or wire speed for the thickness first — roughly 40 amps per millimetre for a single-pass fillet on mild steel — then adjust the voltage until the arc makes a steady crackle. A popping, stuttering arc means the voltage is too low; a hissing, wandering arc with a wide flat bead means it is too high.

How long can E7018 rods stay out of the oven?

Treat four hours of exposure at shop-floor conditions as the maximum before re-drying, and considerably less in wet weather. Re-dry at 260 to 430 °C for one to two hours following the manufacturer’s figure, and do not re-dry the same rods repeatedly. In Malaysian humidity a portable rod oven costs less than a single rejected structural joint.

What lens shade do I need for welding?

Shade 10 to 11 for stick welding up to 175 amps, 12 for 175 to 300 amps, and 13 above that. TIG follows a similar scale from shade 10 at low amperage. Oxy-fuel cutting needs shade 5 to 7. Always pick the darkest shade through which you can still see the weld pool clearly.

Where can I buy welding electrodes and consumables in Perlis and Kedah?

Bann Edar Sdn. Bhd. stocks welding electrodes, MIG wire, tungsten, safety equipment, welding machines and MOX-Linde industrial gas at branches in Kangar, Perlis and Sungai Petani, Kedah. Call 04-976 5570 or WhatsApp 019-470 9929.

Disclaimer. The figures and recommendations on this page are general guidance for planning and set-up only. They are not a substitute for the manufacturer’s data sheet, an approved welding procedure or the applicable standard, and they cannot account for the conditions of your particular job. You remain responsible for checking every figure before you rely on it. Bann Edar Sdn. Bhd. accepts no liability for any loss, damage or injury arising from the use of this tool.

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