GOST 3916.1-2018 in English

Grades, bond classes and surface finish

Designation (3.3–3.4) gives product, species of the outer plies, bond class, face grades, emission class, finish, size and the standard — for example Plywood, birch FK, I/III, E1, Sh2, 2440 × 1525 × 9 GOST 3916.1-2018.

Sizes and tolerances

Table 1 — length and width, mm

Other lengths and widths may be made by agreement between manufacturer and customer.

Table 2 — thickness, mm

Squareness (3.2.2)

Sheets are cut square. Out-of-square not more than 2 mm per 1 m of edge length.

Edge straightness (3.2.3)

Deviation from a straight edge not more than 2 mm per 1 m of sheet length.

Veneer, plies and repairs

• Species (4.1.1). Outer plies of rotary-cut hardwood veneer — birch, alder, maple, elm, beech, aspen, poplar or linden. Inner plies may also be softwood — pine, spruce, fir, larch or cedar. Low-toxicity thermosetting resins. Plywood takes the name of the species of its outer plies.
• Balance (4.1.1). Plies placed symmetrically about the centre are of the same species and thickness, with the same grain direction. With an even number of plies, the two middle plies run parallel.
• Faces (4.1.2). Defects in the outer plies may not exceed the limits of Table 3.
• Inner plies (4.1.3). Defects are permitted that do not affect the quality and dimensions required by the standard. The missing-veneer limit of Table 3, item 13, applies to inner plies as well (Table 3, note 1).
• Face strips (4.1.5). Up to 1525 mm wide, an E face may be two strips joined at the centre; 1525 mm and wider, three strips of equal width. Grade I and II faces may be any number of strips. For E, I and II, joints run parallel to the edges and strips are colour-matched.
• Repairs (4.1.6). Veneer inserts must fit the surface, hold firmly and match the species and grain direction of the face; in grade II they must also match its colour. Putties are colour-matched to the grade, must take an overlay, must not crumble when machined and must not crack when the plywood is bent.

Table 3 — wood defects and processing defects in the outer plies

Limits per face grade. Where the original merges grades into one cell, the cell spans those columns here too. Defect names follow the referenced terminology standards (GOST 2140, 15812, 30427).

Bond strength, physical properties, formaldehyde

Table 4 — glue-line shear strength

FK is tested after soaking the specimens in water for 24 h; FSF after boiling in water for 1 h, or for 6 h by agreement. Wood failure is assessed visually.

Table 5 — physical and mechanical properties (FK and FSF)

Items 4 onwards (the table continues to thermal, acoustic, biological and fire properties) are selected by agreement between manufacturer and customer. Item 5 is printed in the original with the unit kJ/m.

Table 6 — formaldehyde emission classes

How a sheet and a pack are identified

• Each sheet (4.5) is marked in indelible paint on the back with the bond class, the grade and the grader’s number.
• Each pack (4.5) carries the country of manufacture, the manufacturer’s name and/or trademark, the plywood designation and the number of sheets. Shipping marks per GOST 14192; additional marking is allowed for export.
• Packs (4.6) weigh not more than 1500 kg, made up separately by species, bond class, grade, emission class, finish and size. Other weights, or no packing, by agreement. Packing must keep the plywood intact in transport and storage.

Batches, sampling and when a batch conforms

Batch (6.1). Plywood is accepted in batches of one species, bond class, grade, emission class, finish and sheet size, covered by one quality document stating the country and manufacturer, the plywood designation and the volume or area of the batch.

Sampling (6.2). Quality and dimensions are checked on a random sample drawn “blind” per GOST 18321, in the quantities of Table 7. Full inspection is possible by agreement.

Conformity (6.5). A batch conforms and is accepted when, in the samples:

• the number of sheets failing on dimensions, squareness, edge straightness, wood defects or processing defects does not exceed the acceptance number of Table 7;
• no sheet has blisters, delamination or bark inclusions;
• formaldehyde emission meets Table 6;
• physical and mechanical properties meet Tables 4 and 5.

Bond, bending and tensile strength are checked for each bond class, thickness and ply count at least once a month, or per batch by agreement (0.1% of sheets, at least one). Formaldehyde emission is checked once every 7 days on one sheet (6.3–6.4).

How each property is measured

7.2 Length and width

Measured at two points parallel to the edges, at least 100 mm from the edges, with a steel tape (GOST 7502) to 1 mm. The result is the mean of the two readings.

7.3 Thickness

Measured at least 25 mm from the edges at the middle of each side of the sheet, to within 0.1 mm, with a thickness gauge (GOST 11358) or micrometer (GOST 6507). The sheet thickness is the mean of the four readings; the variation in sheet is the largest reading minus the smallest.

7.4 Moisture content

Per GOST 9621.

7.5 Glue-line shear strength

Per GOST 9624.

7.6–7.7 Bending and tensile strength

Per GOST 9625 and GOST 9622.

7.8 Formaldehyde

Content per GOST 27678 (the arbitration method); emission into air per GOST 30255 or GOST 32155.

7.10 Wood and processing defects

Measured per GOST 30427 and GOST 2140.

7.11 Edge straightness

The largest gap between the sheet edge and a steel straightedge (GOST 427), measured with a feeler gauge (GOST 8925) to 0.2 mm.

7.12 Squareness

Per GOST 30427.

7.1 Sampling of specimens

Per GOST 9620, GOST 30255, GOST 32155 and Annex A of the standard (Annex A calls for at least 4 specimens for moisture content).

Transport, storage and the manufacturer’s guarantee

• Transport (8.1). By any mode of transport under the rules for that mode, always protected from rain and snow.
• Storage (8.2). In horizontal packs on pallets or timber bearers, in closed premises, at −40 °C to +50 °C and relative air humidity not above 80%.
• Manufacturer’s guarantee (9). The manufacturer guarantees conformity with the standard provided the transport and storage conditions are observed. The guaranteed storage life is three years for FK and five years for FSF from receipt by the customer.