ESAB solid MIG wire: which one do you need?

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If your MIG welding stops and starts with birdnesting, burnback or an arc that wanders from one spool to the next, the wire is often where the problem starts. ESAB has been making welding consumables since 1904, and its mild steel solid wires are made under tightly controlled processes so they feed smoothly and weld the same way, spool after spool. Here’s how the range breaks down and which wire suits your work.

See our full MIG wire range

Why the wire matters

A MIG wire has two jobs: feed through the liner without snagging, and melt into a stable, predictable arc. Small variations in diameter, surface finish or cast (the natural curve the wire takes off the spool) show up as erratic feeding, spatter and stoppages, and those cost time on any production line. ESAB controls its raw materials, wire dimensions and surface quality so each spool behaves like the last, whether you’re welding by hand or running a robot cell.

Manual MIG welding a mild steel joint with ESAB solid wire — Consistent wire means a steady arc and fewer stoppages. Image: ESAB.

Copper-coated or non-copper-coated?

ESAB’s mild steel solid wires come in two families, and both are offered in G3Si1 and G4Si1 grades.

Copper-coated: OK Autrod. The traditional choice. The thin copper layer protects the wire from rust on the shelf and helps current transfer at the contact tip. OK Autrod 12.51 is the everyday all-rounder for general fabrication.
Non-copper-coated: OK AristoRod. No copper means no copper flakes building up in your liner and contact tips, so there’s less cleaning and fewer feeding problems over a long shift. ESAB’s own testing found OK AristoRod 12.50 needs up to 45% less feeding force in a constrained conduit than the copper-coated and non-copper-coated competitor wires it was tested against. That makes it a strong choice for long or push-pull torches, robots and mechanised welding.

ESAB OK Autrod 12.51 copper-coated mild steel MIG wire spool and box — OK Autrod 12.51: the copper-coated all-rounder. Image: ESAB.

Label on a spool of ESAB OK AristoRod non-copper-coated MIG wire — OK AristoRod: bright, non-copper-coated wire for clean, low-friction feeding. Image: ESAB.

G3Si1 or G4Si1?

The grade tells you how much manganese and silicon is in the wire. G3Si1 wires (OK Autrod 12.51 and OK AristoRod 12.50) suit most mild steel work on clean or lightly scaled plate. G4Si1 wires (OK Autrod 12.64 and OK AristoRod 12.63) carry a little more of both, which gives slightly higher strength and better tolerance of mill scale and rust, and helps the weld pool wet out at higher currents. If you’re not sure, G3Si1 is the safe starting point.

What we stock

Wire	Grade	Coating	Sizes on our site
OK Autrod 12.51	G3Si1	Copper-coated	0.8 mm 5 kg, 1.0 mm 5 kg
OK AristoRod 12.50	G3Si1	Non-copper-coated	0.8 mm 5 kg, 1.0 mm 5 kg, 1.2 mm 15 kg
OK Autrod 12.64	G4Si1	Copper-coated	To order: call us
OK AristoRod 12.63	G4Si1	Non-copper-coated	To order: call us

Looking for a budget-friendly 15 kg spool for general work? ESAB Weld G3Si1 is also available in 0.8 mm, 1.0 mm and 1.2 mm.

Made in Europe

ESAB makes its mild steel solid wire range at its Vamberk plant in Czechia, so supply is close to home and backed by local support.

Aerial view of the ESAB solid wire plant in Vamberk, Czechia — ESAB’s solid wire plant in Vamberk, Czechia. Image: ESAB.

Need help choosing?

Tell us what you’re welding, your machine and how you weld (manual, mechanised or robotic) and we’ll match the right wire, size and spool for you. Call us on 0141 959 5666, email info@weldsafe.co.uk, or browse our MIG wire range.