What is the primary function of a portable jig saw?

The primary function of a portable jig saw is to make irregular cuts. This tool is specifically designed for cutting intricate shapes and curves in a variety of materials, including wood, metal, and plastic. Its versatility allows it to navigate tight corners and provide detailed cutting that other saws may not achieve as effectively. The jig saw's wide range of blade options enables it to cut through different thicknesses and types of material, offering precision in tasks that involve detailed craftsmanship or design work.

In contrast, the other options do not accurately describe the function of a jig saw. Smoothing surfaces typically involves tools like sanders, which are designed to refine the texture of material after cutting. Cutting limbs from shrubbery is a task suited for pruning shears or hedge trimmers, while turning nuts and bolts is the domain of wrenches or socket sets. Each of these tools is specialized for particular tasks, highlighting the unique purpose of the portable jig saw in achieving irregular cuts.