*Russian Birch (Baltic Birch) Grading Standards

*Russian Birch (Baltic Birch)

Russian Birch plywood is desired for its multiple plies of birch veneer that provide superior stability and strength. This panel is an exceptional performer when strength is desired, when either the face veneer or panel edges are exposed, or when a pleasing edge appearance is needed. Russian Birch plywood is typically produced with all birch veneers.

Product Properties
Russian Birch plywood is produced in a wide variety of thicknesses and sizes. Panel thickness is available in the following variations (mm): 3, 4, 5, 6, 8, 9, 10, 11, 12, 15, 18, 21, 24, 25, 28, and 30mm. Depending on the requirements on thickness and tolerance, plywood can have decimal thickness, e.g., 11.2mm.

Grading Standards

Plywood panels can have faces and backs of different grades. In other words, the grade of panel with a BB face and a CP back would be BB/CP. Below is a generally description of the Russian Birch 10.55-71 grade specifications.

 

B – Select one-piece face has a uniform appearance and is free from defect. This face grade is uniformly sanded.

 

 

BB – One-piece face generally light and uniform in color. Pin knots and small sound tight knots are allowed. Occasional “football” patches are color matched to the veneer. Sanding is smooth.

 

 

CP – One-piece face similar to grade BB in quality. Sound knots and patches may be more common than BB grade. Small open splits, knot holes and double patches are allowed. May have some streaks and discoloration. Sanding is smooth.

 

 

C – Open defects, all sound defects, streaks and discoloration allowed. Does not have to be sanded.

Additional grading information on Russian Birch plywood

Birch Face veneer qualities are according to SFS 2413 (= Quality requirements for appearance of plywood with outer plies of birch). The more exact quality description must be checked from this standard.

A   

High quality veneer for varnishing. Availability of grade A is very limited. In practice, grade B is the best we can regularly offer.

I (B)   

Recommended for surfaces to be lacquered. A few pin knots are permitted up to an individual maximum diameter of 6 mm, as there is slight variation in color.

In standard sizes up to 1250 x 2500 mm, the outer ply shall be of one veneer. The veneers forming the outer plies of grade I panels larger than 1250 x 2500 mm are not matched for color.

II (S)   

Recommended for surfaces to be painted. A uniform grade permitting limited number of sound knots up to an individual maximum diameter of 20 mm, and small knots up to an individual maximum dimater of 10 mm without restriction.

Discoloration and joints are permitted as well as limited number of closed or repaired splits.

III (BB)   

A grade commonly used for construction purposes, or interior paint finishes. Minor surface defects are repaired with synthetic filler. A few sound knots are permitted up to an individual maximum diameter of 25 mm and other knots up to an individual maximum diameter of 6 mm. Variations in color are permitted.

Patches, joints and limited number of closed or repaired splits are permitted.

IV (WG)   

A grade suitable for end uses where the surface appearance of the panel is not important. Panels are unrepaired and open splits/knot holes are permitted without limitation.

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