K5/D127-A4 is a type of Kraftberg, a high-performance, lightweight alloy developed for automotive, aerospace, and industrial applications. It features extremely good creep resistance, excellent fatigue fatigue strength, and a high resistance to corrosion. The material is easily machined and welded, and is an excellent choice for components in demanding, high-load applications. It is often used in the manufacture of high-end automotive exhaust and body parts, as well as in the construction of aircraft and boats.