Every shop that runs SMAW with E7018 electrodes needs to know their true deposited cost — not the purchase price per rod. IronKit's Weld Cost Calculator revealed that at $0.85/lb electrode cost, only 62% of the purchased electrode ends up as weld metal (stub loss + spatter + slag). This means the true wire cost per pound deposited is $1.37/lb — 61% higher than the sticker price. The shop was previously estimating at rod price, which understated material cost on their SMAW bids by nearly $0.50/lb deposited. The cost sheet also compared 3/32", 1/8", and 5/32" electrode sizes across three fillet sizes.
Frequently Asked Questions
Why is E7018 deposition efficiency only 62%?
E7018 loses material in three ways: (1) stub loss — the last 1–1.5" of every electrode is discarded, costing ~10%; (2) slag — the flux coating forms a slag layer that is removed and discarded, accounting for ~18%; (3) spatter — ~10% of arc metal is scattered as spatter. Combined, 38% of the electrode purchase weight never becomes weld metal.
How does SMAW deposition compare to GMAW?
GMAW ER70S-6 runs at 93–95% deposition efficiency — nearly all wire becomes weld metal. SMAW E7018 at 62% is significantly lower. However, SMAW has lower equipment cost, better portability, and better performance in windy conditions. The cost premium is real but SMAW remains competitive for field work.
What deposition rate should I use for E7018 1/8"?
At 130–160 A on a 1/4" fillet, expect 3.2–3.8 lb/hr arc-on deposition rate. Applied productivity (arc-on vs. shift time) reduces this to 1.5–2.0 lb/hr for structural shop work. Use arc-on rate for cost calculations, then apply a realistic arc efficiency factor.
When is SMAW still the right choice for structural work?
SMAW remains the right choice for: field work in windy or wet conditions, remote locations without reliable power, tack welding and repair work, out-of-position welds where GMAW gun angle is awkward, and root passes on thick plate where a tight root opening requires a precise strike. The higher consumable cost is offset by setup flexibility.