NEN EN 1611-1 : 1999 AMD 1 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