A pick-up tool is used to retrieve objects that are in hard-to-reach areas (e.g. mechanics use them to retrieve objects from engines). As the object/s being retrieved are often ferromagnetic materials, pick-up tools have a magnet on the end to attract the object.
Depending on the strength of the magnet in the pick-up tool, it can be used to pick up a variation of objects from simple nuts and bolts to heavier tools such as pliers.
Larger pick-up tools can also be used to collect a number of objects at a time. This can be useful if you need to pick up a lot of screws or nails off the ground to prevent injury or damage.
