Which of the following are the disadvantages of SMAW?

• A. Low temperature arc
• B. Bulky, heavy equipment
• C. Easy to burn through metals lighter than 18 gauge
• D. All the above

Answer: (C)

SMAW’s heat input can be difficult to control precisely, and when you’re working with very thin metal, that heat tends to stay concentrated at the arc and quickly raises the metal temperature beyond what the sheet can safely dissipate. Metals lighter than about 18 gauge have little mass to absorb that energy, so holes or burn-through are a real risk. That makes thin-gauge welding a notable drawback of SMAW, which is why burning through thin metal is cited as a disadvantage.

The other points aren’t universally true drawbacks. The arc in SMAW is very hot, not low-temperature, so “low temperature arc” isn’t accurate. And although some older or larger setups can feel bulky, modern SMAW gear can be quite portable, so equipment size isn’t an inherent, universal disadvantage.