As is known by everyone, lower weights and higher temperature resistances are needed for most components, especially engine parts, to endure high stresses during the flight. Therefore, Aluminum is one of the most suitable materials for aerospace parts because of its great properties of resistance, light-weight, easy-machined and low raw material cost.
In some occasions, other materials are also availble for CNC machining, such as stainless steel for engine parts that require higher heat resistance, and titanium alloy for even higher strength and resistance requirement than aluminum.