This European Standard specifies a method of strength grading tropical hardwood visually for structural use.
The permissible limits of characteristics for a single visual strength grade of timber are specified, designated “Structural Tropical Hardwood” (STH) grade.
The method is only suitable for pieces of timber with a rectangular cross-section that is constant along their lengths.
Characteristics related to durability are not covered in this standard. For some end uses, additional requirements may be specified at the time of grading, e.g. sapwood exclusion.