Medium power transformers are responsible of the great part of total power losses in the grid. With EN50588-1 regulation, no-load and load losses have strictly classified fo(dagger)r high-efficient transformer designs. Manufacturers are currently focusing on obtaining the most efficient design with minimum cost. In this paper, manufacturing feasibilities of Si-Fe graded distribution transformers, considering the requirements of EN50588-1 regulation, are investigated. Eleven different steel types in three grades are evaluated using twenty different electrical designs. A prototype transformer was both simulated and experimentally tested to verify the results of design studies. Obtained results show that the manufacturing of A(0) and AA(0) class transformers are feasible using Si-Fe grades with suitable manufacturing methods. However, amorphous materials seem to be a mandatory choice for AAA(0) class transformers in technical manner.