OAK GRADES SMELAWOOD

		Width, 67-130 mm	Width, 130-305 mm
	1 Grade (A / Select)	— sound knots up to 10 mm — black pin knots up to 3 mm — uniform color	— sound knots up to 3 mm — black pin knots up to 3 mm — uniform color
	2 Grade (B / Nature)	— sound knots up to 20 mm — black knots and holes up to 10 mm, but at least 10 mm from the edges — natural changes color and structure	— sound knots up to 30 mm — black knots and holes up to 10 mm, but at least 10 mm from the edges — natural changes color and structure
	3 Grade (C / Nature)	— sound knots up to 50 mm — black knots and holes up to 20 mm — holes and knots up to 10 mm, but at least 10 mm from the edges — unexpressed core without a crack and a sharp change in color up to 1/3 of the length of the lamella — natural changes color	— sound knots up to 70 mm — black knots and holes up to 40 mm — holes and knots up to 20 mm, but at least 10 mm from the edges — heart core — cracks up to 200 mm — natural changes colour — grown bark up to 50 mm
	4 Grade (D / Rustic)	— sound knots up to 50 mm — black knots up to 50 mm — holes and dropped out knots up to 30 mm, but at least 10 mm from the edges — heart core is allowed along the whole length — cracks which do not destroy the lamella’s structure — strong change color — grown bark without rot	— sound knots up to 90 mm — black knots up to 60 mm — holes and dropped out knots up to 40 mm, but at least 10 mm from the edges — heart core is allowed along the whole length — cracks which do not destroy the lamella’s structure — strong change color — grown bark without rot
	5 Grade (2D / Rustic)		— knots are allowed, including side knots — dark knots without restrictions — single holes not in groups up to 50 mm — heart core — grown bark up to 200 mm — natural changes in colour

European Oak

Botanic name: Quercus petraea (MATT) LIEBL – Quercus robur L.
Place of the origin: Eastern Europe
Color: from yellow brown to golden yellow
The direction of fibre: straight, sometime with deviations

Stability: medium high
Specific weight: 0,55-0,97 g/cm3
Brinell Scale: 3,40 kg/mm2