Machine screws are fully threaded fasteners with a uniform diameter the entire length of the shaft. They are primarily used to fasten metal parts together. Machine screws, sometimes called stove bolts, have a blunt end and tend to be smaller in size than other bolts. They are either fastened with a nut or driven into a tapped hole. Machine screws come in a large variety of head styles, drives, thread types and materials to cover a wide range of applications.