Specifies grade requirements for structural grades Nos 1 to 5 for softwoods graded for adequacy of strength. Derived from these grades are stud grades and lintel grades which provide the straighter material required for studs and lintels; and structural appearance grades which have additional limitations on the visual blemishes allowed in structural members exposed to view. Appendices set out the stress grades for each structural grade of the major species covered by the Standard and explain the relationship between strength groups, structural grades and stress grades.