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Grades

Blatic Russian Birch GRADES

• BB/BB: Whole piece face and back veneer. Face veneers are graded clear and free of defects with a light-white uniform color. Inner cores are solid birch single piece veneers.
• BB/BB: Whole piece face and back. Tight pin knots may be present and inner cores are solid single piece veneers.
• BB/CP: Whole piece face and back. The “CP” back veneers are downgraded from “BB” grade veneers. Inner cores are solid birch single piece veneers.
• CP/CP: Whole piece face and back. The panel is sound both sides and designed for laminating.
• C/C: Grade calls for patches, open knots and small veneer splits. This panel is not sanded and is primarily used in structural applications.Shop Grades: Shop panels are also offered in the full 5×5 format in all grades listed above.

Simplified Russian plywood grading rules in accordance with GOST 10.55-71 and GOST 3916.1-96 are presented below:

Grade CP

10.55-71	Grade B	Grade BB	Grade CP	Grade C
3916.1-96	Grade I	Grade II	Grade III	Grade IV
Pin knots	Not more than 3 per square meter	Allowed	Allowed	Allowed
Sound intergrown knots	Allowed with diameter not more than 15 mm	Allowed with diameter not more than 25	Allowed with cracks not wider than 1,5 mm	Allowed
Other knots	Allowed with maximum diameter 6 mm	Allowed with maximum diameter 6 mm	Allowed with maximum diameter 6 mm	Allowed with maximum diameter 40 mm
Closed splits	Maximum length 200 mm	Maximum length 200 mm	Allowed	Allowed
Open splits	Not allowed	Allowed with maximum size 200*2 mm	Allowed with maximum size 300*2 mm	Allowed with maximum width 10 mm
Light discoloration	Allowed not more than 5% of the surface	Allowed	Allowed	Allowed
Heavy discoloration	Not allowed	Not allowed	Not allowed	Allowed
Glue penetration (through faces)	Not allowed	Allowed not more than 2% of the surface of the panel	Allowed not more than 5% of the surface of the panel	Allowed
Veneer overlapping	Not allowed	Allowed with maximum length 100 mm	Allowed with maximum length 200 mm	Allowed
Repairing by plugs	Not allowed	Allowed with single plugs	Allowed with double plugs	Allowed with double plugs
Sanding through faces	Not allowed	Not allowed	Not allowed	Allowed

Russian (Baltic) Birch Grade Rules
B Grade	One piece sanded face with even color. No patches, voids or mineral streaks allowed.
BB Grade	One piece sanded face with generally even color. Slight pin knots and mineral streaks allowed. Open knots and defects are cut out and replaced with oval patches.
CP Grade	This is a fall down from BB with more patches on the face that may not always be matched for color. Splits less that 0.5 mm are allowed.
C Grade	Un-sanded face that allows patches, open knots and veneer splits.
NOTE: Russian Birch panels are a consistent specie throughout the panel (core and face and back veneer).