The molten weld pool width should be twice the diameter of the electrode core wire.

• A. Half the diameter
• B. The same diameter
• C. Twice the diameter
• D. Three times the diameter

Answer: (C)

Bead geometry and heat control in SMAW. A practical rule of thumb is that the molten weld pool width should be about twice the diameter of the electrode core wire. This ratio balances how much metal is produced and how heat is distributed in the weld.

Why this fits: the diameter of the core wire indicates how much filler metal is being deposited per unit length and how much heat is required to melt it. If the pool is about twice that diameter, there’s enough molten metal to fill the joint and form a proper bead with good fusion to the base metal, while keeping the heat input under control. If the pool is narrower, you risk insufficient filler and weak fusion. If it’s much wider, you risk excessive heat, distortion, and possible burn-through. So the twice-diameter guideline helps produce a solid, well-formed weld bead.