NS EN 1611-1 : 1999 + A1 2002

Foreword
1 Scope
2 Normative references
3 Definitions
4 Rules for grading
  4.1 General rules
  4.2 Determination of features
5 Tables of rules for grading
  Table 1: Grading on two faces - Maximum accepted
           values for knots for European spruces,
           firs, pines and Douglas firs
  Table 2: Grading on four sides - Maximum accepted
           values for knots for European spruces,
           firs, pines and Douglas firs
  Table 3: Grading on two faces or four sides -
           Maximum accepted values of other features
           for European spruces, firs, pines and
           Douglas firs

Specifies appearance grades for European spruces, firs, pines, Douglas fir and larches. Applies to dry and green sawn timber but not to the strength grading of structural timber.