Mechanical engineering is an engineering discipline that combines engineering physics and mathematics principles with materials science to design, analyze, manufacture, and maintain mechanical systems. It is one of the oldest and broadest of the engineering disciplines or Mechanical engineering is a discipline of engineering that deals with the study, design, development, construction, and testing of mechanical and thermal sensors and devices, including tools, engines, and machines. Mechanical engineering careers center on creating technologies to meet a wide range of human needs. A career in mechanical engineering allows you to build a better future for you, and for the world. This explains why 89% of engineers have high levels of job satisfaction, and would choose the same career path again.