Abstract
	The basis of embrittlement of continuously cast products (slabs, blocks, billets) in connection with the development of micro cracks  and cracks in the surface skin is analyzed and described in the contribution.
	Basic starting points and provisions of the embrittlement of continuously cast products, risk factors of hot cracking  and probable processes of under solidus recrystallization grain growth at high temperature from 1300 up to 1400 ?C during continuous casting are presented. 
	Based on the analysis a conclusion made, the majority of transversal, branched, and longitudinal cracks is formed in the mould, and these cracks can, though need not,  grow on  deeper into the slab either in the secondary cooling zone  or in the straightening process.
	The crack growth during continuous casting is controlled by the ability of the matrix to relax stress peaks in front of crack tips. The stress relaxation is due to the  plastic deformation  (creep),   the precipitation of carbidic, nitridic or carbonitridic phases or segregation of S, and/or P or other surface active elements.