Clear-Wood Tests
small, clear, straight-grained specimens
- dimension lumber - 2x2 to 4x16 - ASTM D2555
- timber - 6x6 and greater - ASTM D245
strength ratio
- reduces clear-wood values by taking into account common defects (knots)
- seasoning adjustment factor is not used for timber
- average FS = 2.5
- FS < 1.25 for 99%, FS < 5 for 1%
2010 Wood Handbook
In-Grade Tests
ASTM D4761 and D1990
73,000 specimens
Reference Design Values
in NDS Supplement
Table Topic 1A sizes 1B-1D section properties 4A-4B visually graded dimension lumber 4C mechanically graded dimension lumber 4D visually graded timbers 4E visually graded decking 4F non-north american lumber