More Related Content
What's hot (20)
Recently uploaded (20)
Gost 8486 86 (quality of sawn timber)
- 1. Sawn softwood Technical requirements in accordance with GOST 8486-86 Number The index, attribute, defect of wood, Requirements for grades its location selective Grade 1 Grade 2 Grade 3 4 grade 1 Wood species coniferous (the specification of the buyer) 2 Nominal length, m: for the domestic market and export from 1.0 to 6.5 with gradation 0,25 for the manufacture of packaging from 0.5 to 0.1 grading for bridge beams 3.25 for export from 0.9 to 6.3 with 0.3 grading 3 Deviations from nominal length, mm. -25 to +50 6 Deviations from nominal thickness and width, mm, nominal sizes: up to 32 mm incl. from -1 to +1 from 40 to 100 mm incl. from -2 to +2 more than 100 mm. -3 to +3 7 The smallest width of the plastic timber unedged, mm, at a nominal thickness: from 16 to 50 mm. 50 from 60 to 100 mm. 60 125 mm or more 60% of thickness Note 1: The dimensions of sawn timber on thickness and width are set to 20% humidity. With more or less moisture content of sawn sizes should be more or less the amount of shrinkage in accordance with GOST 6782.1-75 8 Knots fused healthy: diameter percentage of width / number of 1 m length pieces.: layer and arris 20 / 2 25 / 3 33 / 4 50 / 4 allowed Edge: allowed at a thickness of 40 mm. 33 / 1 50 / 2 67 / 2 add. / 2 40 mm and more 25 (but not 33 / 2 50 / 3 add. / 3 more than 15 mm) / 2 Knots partially fused and unjoint diameter as a percentage of the width / number of 1 m length (in the amount of fused), ea.: 9 layer and arris 12,5 / 2 20 / 2 25 / 3 33 / 3 50 / 4 Edge: at a thickness of 40 mm. 25 / 1 33 / 1 50 / 2 add. / 2 add. / 2 40 mm and more 10 mm / 1 25 / 2 33 / 2 67 / 2 add. / 3 10 Knots decayed and rotten not allowed diameter - on standards for intergrown and unjoint knots, the number - no more than half of their permitted number of Note 2: The diameter of the knot is measured by the distance between two lines related to knot parallel to the longitudinal axis of the timber. Note 3: Knots with a diameter less than 50% of the allowable values are not taken into account. Note 4: Knot normalized as asymphytous knot in a perfect grade is not allowed. Note 5: The timber length of 3 m may be a twig with a diameter of Standards adjacent lower grade. Note 6: In the section of length equal to the width of the timber, the sum of the sizes of knots in a straight line across this area in any direction shall not exceed the allowable diameter of the knot. Note 7: The bars (thickness and width of 100 mm or more) the number of knots is not standardized. Face cracks and edge, including go to the end, length, percentage of length of sawn allowed 11 timber: shallow 16 25 33 50 deep 10 16 33 50 Face cracks cross-cutting, including going on the end: 12 Length, mm. 100 150 200 - - length, percentage of length n / m. - - - 16 25 13 Cracks face (except for cracks from not allowed 25 33 50 allowed shrinkage), length, percentage of the (One of the ends) width of the timber Note 9: The permissible sizes of cracks are set for lumber with a moisture content of 22%. At greater moisture these sizes decrease by half. 14 Slope of grain,% 5 allowed 15 percentage of area of sawn timber not allowed 20 allowed Resin pockets: 16 amount per 1 m of length n / m, ea. A 2 4 allowed length of the pocket (on one side of 50 allowed timber), mm.
- 2. 17 Core and dual core not allowed allowed without radial cracks in lumber not allowed allowed thickness of 40 mm or more Bark (simple): 18 width, the width of the lumber not allowed 10 20 25 allowed length, percentage of length of sawn 5 10 10 timber 19 Cancer, length, percentage of length of not allowed 20 but not more 33 allowed sawn timber than 1 m. 20 Fungus heartwood stains, area, not allowed 10 20 allowed percentage of the area of timber Sapwood mushroom painting and mold: 21 surface not allowed not allowed deep area, percentage of the area of 10 20 50 not timber allowed 22 Rot: not allowed variegated heartwood rot sieve in the not allowed 10 form of spots and stripes, area, percentage of the area of timber 23 Wormholes, the number of holes per 1 not allowed (except for 2 3 6 m length of sawn timber, ea. the shallow part of the wany) 24 Foreign inclusions not allowed Acute wane: 25 width of sawn layer, per cent of width not allowed 50 sawn timber length of the sawn edge, percentage of 25 length of sawn timber Dumb wane: on faces and edges with no limit on the 16 16 16 33 26 length, size of sawn, percentage of allowed width edges in some areas, the amount of not 33 33 33 66 sawn, percentage of width length of the section, percentage of 16 16 16 25 length of sawn timber 27 Butt trimming, percentage of width or 5 5 5 5 5 thickness of the p / m. 28 Risks undulation, tear-out, depth, mm. not a deviation from the nominal thickness 3 allowed or width (item 5) 29 Crook longitudinal on layer and an 0.20 0.20 0.20 0.40 allowed edge, sag, the percentages of the width of the timber 30 Crook transverse, sag, the percentages A A A 2 allowed of the width of the timber Note 10: Limits are set crook for lumber moisture content of 22%. At greater humidity rate reduced by half. Note 11: Defects of wood, not mentioned in the table are allowed. Note 12: Sawn timber are delivered dry (moisture content not exceeding 22%), raw or not antiseptized. Note 13: Assessment of quality lumber, with the exception of the deck should provodits on layer or edge, the worst for this board.