Steel bridges constitute the second most bridges in the U.S. while the number of deficient bridges are growing. Currently, the majority number of current bridge inspections are done manually by inspectors which require significant amount of human resources along with expensive and specialized equipment. Moreover, it is difficult and dangerous for inspectors to inspect large bridges with high structures. In this paper, we propose a new design and implementation of a robotic system that can be used for steel bridge inspection. The robot consists of four magnetic wheels which create adhesion to steel surface. It is able to carry multiple sensors for navigation and mapping. Collected data are sent to the ground station for live monitoring as well as further processing. In addition, magnetic field and range sensors are also integrated to enable robot to move safely on steel surfaces. Results with physical tests on real steel structures are shown to validate the feasibility of robot design.