The article discusses the dependence of mechanical flexural strength porcelain stoneware on the content and type of phases composing his ceramic body. It was found that the high strength characteristics of products is achieved by increasing the amount of content of crystalline phases and glass phase. An increase in the number of metakaolinite consisting stoneware contrary, leads to a reduction in its strength.

Keywords: porcelain gres, structure, crystalline phase, amorphous phase, glass phase, the flexural strength