Short circuit transfer (GMAW-S) uses what level of voltage and heat input?

• A. High, High
• B. Low, Low
• C. High, Low
• D. Low, High

Answer: (B)

Short circuit transfer in GMAW-S uses a very short, frequent arc that keeps the welding voltage low. Because the arc is short and energy per transfer is limited, the overall heat input into the workpiece is low. This cooler, gentler heat helps when welding thin sheet metal, reducing distortion and burn-through and giving the welder better control. Higher heat input and voltage are more typical of other transfer modes (like spray transfer), which deliver more energy and are less suited to thin materials. So the combination of low voltage and low heat input is what defines GMAW-S short circuit transfer.