AG Mechanics CDE Practice Exam 2026 - Free AG Mechanics Practice Questions and Study Guide

The process that does not involve the use of an electrical arc is oxy-fuel welding. Oxy-fuel welding relies on the combustion of a fuel gas (usually acetylene) mixed with oxygen to produce a flame that melts the base metal, allowing for fusion. This method requires careful control of the flame and the addition of a filler rod if necessary, but it does not utilize an electrical arc for its operation.

In contrast, the other processes listed—flux-cored arc welding, gas tungsten arc welding, and shielded metal arc welding—all rely on electric arcs. Each of these methods generates an arc between the electrode and the workpiece, which produces the intense heat necessary for melting the metals to accomplish welding. This fundamental difference in the way heat is generated is why oxy-fuel welding stands apart from the others in this question.