In the context of metal forming, what does the term 'bump' refer to?

The term 'bump' in the context of metal forming specifically refers to a technique for shaping metal sheets. This process involves putting controlled pressure on the material to create localized deformations, which results in the desired shape or contour of the metal.

This shaping technique is significant in sheet metal work because it allows for more complex geometries to be formed without compromising the material’s integrity. For example, creating rounded edges or specific contours on a panel can enhance both the aesthetic and aerodynamic qualities of the final product.

When considering the other options, the processes involved in sharpening edges, increasing tensile strength, or joining metal sheets do not align with the definition of 'bump' as a shaping technique. Each of those processes involves different methods and objectives, thus differentiating them clearly from the shaping function that 'bump' describes.