A magnetic tool to enable a robot arm to grip a metallic workpiece includes a hollow housing having a coupling member adapted to attach the tool to the robotic arm. A sleeve depends from the housing having a shaft slidably received therein. The shaft has a first end disposed in the housing and a second end extending axially outwardly from an open end of the sleeve. A magnetic member is disposed on the second end of the shaft. The magnetic member includes a main body having a cavity formed therein. A magnet is slidably disposed within the cavity and attached to an actuator adapted to adjust the distance between the magnet and an inner surface of a magnetic face of the main body of the magnetic member to vary the magnetic attraction force at the magnetic face.