Rotary friction welding (RFW) one of the methods of friction welding, the classic way of which uses the work of friction to create a not separable weld. Typically one welded element is rotated to the other and forge (pressed down by axial force). The heating of the material is caused by friction work and creates a permanent connection. In this method can be welded the same, dissimilar, or composite and non-metallic materials. The friction welding methods of are often considered as solid-state welding.