In industry, many transmission pipelines are made of ferromagnetic steel. They are prone to corrosion that can lead to serious accidents. On the other hand, ferromagnetic properties of these steel pipes enable us to use the magnetic flux leakage (MFL) method to inspect defects caused by corrosion with the main advantage of having high detection speed. For connected pipes, the inspectors detect defects from the outside of pipes by pushing a handheld MFL inspection device along the test pipe. The requirements for this device are to have a sufficiently strong magnetization field for yielding strong MFL signal, have a uniform magnetic field zone between two magnetic poles, have a limited mass and have a moderate magnetic attraction. The optimization of the configuration of the device to meet the above requirements has been drawn from simulation and experimental studies.