One process involves a patented mandrel for making elastomeric articles. This process involves winding filaments under tension over a rotating mandrel. Sheets of prepreg material are wrapped around a steel or aluminium mandrel. Aircraft designed with these rivets use rivet strength figures measured with the mandrel removed. A bending mandrel has a narrow geometry. Performance automotive or motorcycle exhaust pipe is a common application for a mandrel. The outer surface of the mandrel forms the inner surface of the form. Exhaust pipes for automobiles are frequently bent using a mandrel during manufacture. "Mounted points" are small grinding wheels bonded onto a mandrel. The process involves winding filaments under tension over a male mandrel. At the same time, the space between the mandrel and outer die walls is increased. The mandrel is held in by the friction forces between the mandrel and the tube. Most cordwood saws consist of a frame, blade, mandrel, cradle, and power source. The component is normally cured at high temperature before removing the mandrel. The structure is cured and the mandrel is removed.