Mechanical engineering involves designing and constructing machines from products like airplanes and chocolate bars to clothing. Mechanical engineers apply scientific principles to practical situations by designing machines using CAD software, meeting with managers to discuss expectations, overseeing machine manufacture and maintenance, testing and repairing machines, and answering client questions. Mechanical engineers typically work long hours in noisy factories or clean offices and earn between $40,000 to $130,000 annually depending on experience and level of expertise. A bachelor's degree in mechanical engineering is the minimum requirement for the field, while master's and PhD degrees are needed for more advanced positions.