Two recycling processes for iron and steel have been proposed. One is the application of thermo-mechanical treatment in which machined scraps are recycled by thermo-mechanical treatment such as hot forging without re-melting of the scraps. It brings not only reduction of energy consumption but also good mechanical properties of the recycled specimens due to grain refinement. The other is recycling from machined scraps to a cellular solid by a sintering process. Cellular solids have a lot of porosities and the porosities are considered to be large defects. Hence, even if defects such as contaminations are contained during recycling process, mechanical properties of a cellular solid are hardly affected by the acquired defects. hi this research, machined scraps of medium carbon steel (Fe-0.45mass% C) were recycled by the two processes and the mechanical properties of the recycled specimens were evaluated.