свойства, изменяющиеся по толщине

цитата из описания стандарта на сталь: http://engineers.ihs.com/document/abstract/DPYWJBAAAAAAAAAA
The primary use of these steels is in tubular joints, stiffened plate construction, and other intersections where portions of the plates will be subject to tension in the thickness direction (Z-direction). Supplementary Requirement S4 provides for through-thickness (Z-direction) testing of plates by the manufacturer and specifies limits for acceptance. Supplementary Requirement S1 provides for ultrasonic examination of the plates by the manufacturer and specifies limits for acceptance.

For applications where through-thickness properties are important but Z-direction testing has not been specified, Supplementary Requirement S5 provides low-sulfur chemistry intended to reduce the size and number of sulfide inclusions in the plate. Supplement Requirement S5 is neither a substitute for S4, Through-Thickness Testing, nor a guarantee of a minimum level of through-thickness ductility.