Stevens
QUALITIES

Pine:
I: Knotless on three sides
II: In 25-mm thick planks the knot size is limited to 10-12mm, depending on the width.
III: In 25-mm planks, the knots should not be bigger than 15mm in diameter (the size of a 1 euro cent piece).
U/S: Joinery quality
V: Better construction quality for visible work
VI: Normal construction quality

Spruce:
U/S: Carpentry quality
V: Better construction quality for visible work
VI: Normal construction quality
SLS: Planed construction wood
Rafters: Planed battens in various dimensions
Laths: Planed laths available in various dimensions

Larch:
I: Knotless on three surfaces
II: In 25-mm thick planks the knot size is limited to 10-12mm, depending on the width.
III: In 25-mm planks, the knots should not be bigger than 15mm in diameter (the size of a 1 euro cent coin).
U/S: Carpentry quality
IV and S/F: Carpentry quality

Southern Yellow Pine:
SAPS (sapwood): Top quality, i.e. defect free wood.
Prime & Better: This is the best quality available in thicker wood (from 2”).
The odd knot on the heart side is permissible.

Oregon Pine:
N° 2 Clear & Better: Top quality carpentry wood with a maximum of 15% N° 3 Clear.
Select & Merchantable SS/GS: This is freshly-sawn construction wood

Western Red Cedar:
N° 2 Clear & Better: This is the top quality carpentry wood with a maximum of 15% N° 3 Clear.
Shingles: Roof and wall cladding.
Planchettes: Planed T&G planks.

Hemlock:
N° 2 Clear & Better: Top quality carpentry wood with a maximum of 15% N° 3 Clear.

Spruce Pine Fir:
CLS: Planed construction wood. Generally J grade.

European Douglas:
Douglas has a standard construction quality.

Slash Pine:
SAPS (sapwood): Top quality, i.e. defect free wood.