What are the dimensions of sawn timber
It's hard to argue that any sawn timber is made from hardwood and coniferous trees. It is much more interesting to trace the patterns, to be more precise, the standards and norms that occur in the manufacture of wood industry products. Let's start, perhaps, with logs, the source material.
Logs are usually called formats with a diameter of not less than 14 centimeters and a length of 4 meters or more. The log is divided into quarters and plates, lying and hunchbacked, this is the simplest sawing. Cutting off the logs 4 slabs, you can get a four-cant wood as a result. The length of each of the listed elements for the most part corresponds to the length of the log, the width depends on the trimming line.
More complex and calculation-demanding sections: unedged boards and edging, which are divided into thick and thin. The beam can be sawn to narrower bars, or to edged boards, a log without sipping the slabs - only on unedged boards. Sawn softwood is rarely longer than 6.5 meters, and hardwoods are longer than 5 .
However, if necessary, by special order, you can get boards or timber up to 9 meters. The remaining sizes of sawn timber are usually determined by the assortment, in accordance with the diameter of the upper cut of the log. Planed sawn timber, which are shpuntovannymi, are thinner by 4 and already by 6 millimeters( for boards), by removing from each surface 2 and from the side faces of 3 millimeters.
What should be the weight of sawn timber
For the most part, the weight of the lumber depends on the wood species. So, for example, conifers are quite heavy because of the resin impregnating them, although it becomes much easier after steaming and dewatering the latter. Oak is heavy in itself, because of its high density, and hazel is very light wood.
In general, it is common to measure the weight of wood industry products in cubic meters. So, for example, on average, the cube of a board with dimensions of 2.5х10х580 centimeters weighs 600 kilograms, without correction for the wood species. Such boards in the cube will be 66 pieces, again without taking into account the breed.
The weight of wood directly depends on the moisture and wood species, as well as on factors such as cavities in the structure, resinity, etc.
As for the bar, the same will weigh the cubic meter with dimensions of 5x5x580 centimeters with the number of 66 pieces, or 5x10x580 centimeters in the amount of 33 pieces. In general, any lumber that can be stacked closely will weigh the same for different sizes, but in different amounts.
For example, a bar 25x30x580 in a cubic meter will be only 2 pieces( more precisely 2.2, but the manufacturer always cuts down), with a total weight of 600 kilograms. If we take as a basis the wood species, the cubic meter of raw pine weighs 890, and the dry one - 470 kilograms, that is, almost 2 times lighter. The cube of raw spruce weighs 790 kilograms, and dry, taking into account the resin remaining in the fibers, is 450 kilograms.
Density of sawn timber and what depends on it
How many of the lumber depends on many of their characteristics, including strength. However, the density itself is directly dependent on the wood species and its moisture content( which varies with the season).However, the cracks do not affect the density of the tree in any way, but significantly reduce the strength, and knots in general considerably increase the density in some areas of the .
In general, the density of wood can be of three types, based on a moisture content of 12%: high density at 750 kg / m3 and more, an average density of 550 to 750 kg / m3 and a low density of 540 kg / m3 and less.
If we consider the rocks separately, then spruce, with the percentage of moisture that we take as the standard, will have a density of 445, and in the dry state 420 kg / m3, although its nominal density is 360. A conditional density is the ratio of the weight of wood in an extremely drystate to its volume at the maximum saturation with moisture.
Birch, for example, has the highest density after oak and beech at 12% humidity - 630 kg / m3( in oak the same figure is 700, and in beech - 650), in its dry state its density is 600, and conditional -500, which is a significant difference. Thus, everything depends on the individual properties of the tree species.