The role of strength and mechanical stability in the assessment of the structural quality steel

New characteristic of resistibility to embrittlement is offered, which displays metal's ability to resist transition from ductile to brittle state. Interconnection between resistibility and strength, as the main mechanical property of metal is considered. It is exhibited that mechanical stability ms K essentially compliments characteristic of strength σ0,2 in terms of estimation of metal's susceptibility to embrittlement by all environment factors. It is ascertained that strength ( σ0,2 , σ2 , B σ ) is key mechanical characteristic of structural steels, which fully controls resistibility to embrittlement together with the characteristic of mechanical stability ms K . Necessity of characteristic of structural quality related to mechanical stability ms K for estimation of strength of structural steels is shown.