Solid MIG Wire vs Gas-Shielded Flux-Core for Production Welding

ER70S-6 solid MIG wire vs E71T-1 flux-core for shop fabrication. Choose based on material thickness, position, and cleanup requirements.

Key Differences

AttributeER70S-6E71T-1
Wire TypeSolid wireTubular wire with flux core
SlagNone - no post-weld cleanupProduces slag that must be chipped
Penetration (per amp)Good with spray transferHigher - flux reactions concentrate arc
Best Thickness RangeSheet metal to 3/8" single pass1/4" and up, multi-pass on heavy plate
Out-of-PositionRequires short-circuit or pulse modeBetter puddle control in all positions
AppearanceClean, smooth - minimal post-weld workRougher with slag lines, requires cleanup
Cost per PoundLower wire cost + gas costHigher wire cost + gas cost
SpatterLow with proper settingsModerate - more anti-spatter compound needed

How ER70S-6 and E71T-1 Work Together

On material under 3/8 inch, ER70S-6 MIG is faster because there is no slag to remove. On material over 3/8 inch, E71T-1 provides deeper penetration per amp and higher deposition rates. For multi-pass heavy plate work, E71T-1 is the production standard. For light gauge and appearance-critical work, ER70S-6 MIG is cleaner.

Common Mistake With Solid MIG Wire

Assuming flux-core is always better for thick steel. On single-pass fillet welds up to 5/16 inch, solid MIG with spray transfer can match or beat flux-core deposition rates with less cleanup. The crossover point where flux-core wins is multi-pass work on thicker joints.

Where to Buy

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ER70S-6 on Amazon

E71T-1 on Amazon

Data sourced from .