Which of the following is NOT a method for forming sheet metal?

The correct answer is that "sliding" is not a recognized method for forming sheet metal. In the context of sheet metal fabrication and shaping, methods typically include bending or folding, shrinking, and crimping.

Bending or folding is a widely used technique that alters the shape of the metal by applying force along a straight line, effectively creating angles or curves in the material. Shrinking involves an intentional reduction of the metal surface area, allowing for more complex shapes and contours to be achieved, typically used when working with compound curves. Crimping refers to the process of folding or indenting the edges of the sheet metal to create a permanent joint or connection, often utilized in ductwork or in decorative applications.

In contrast, "sliding" does not directly pertain to a method of forming sheet metal. Rather, it may describe a process related to movement or alignment rather than shaping the material itself. This distinction is essential for understanding the various techniques employed in the precise manipulation of sheet metal.