The specific gravity of wood is unstable. This value directly depends on the moisture content of the rock. Density indices can vary widely even for a single tree species. Therefore, the values displayed in the tables are just generalized data. In practice, the values of the density of wood differ from the tabulated values averaged in the literature and this correction is not considered a mistake.
Wood density table
Wood species | Density
wood
(kg / m 3 ) | Limit
density
wood
(kg / m 3 ) |
Ebony
(black) | 1255 | 1255 |
Iron | 1255 | 1175-1385 |
Oak | 805 | 695-1025 |
Red tree | 800 | 555-1050 |
Ash | 755 | 525-955 |
Rowan | 725 | 685-885 |
Apple tree | 715 | 665-840 |
Beech | 675 | 625-815 |
Acacia | 665 | 575-845 |
Elm | 655 | 555-815 |
Larch | 630 | 545-660 |
Maple | 655 | 535-810 |
Birch | 645 | 510-765 |
Pear | 655 | 615-730 |
Chestnut | 645 | 600-710 |
Cedar | 560 | 550-575 |
Pine | 520 | 300-750 |
Linden | 500 | 450-800 |
Alder | 505 | 475-585 |
Aspen | 475 | 465-545 |
Willow | 480 | 450-580 |
Spruce | 445 | 365-755 |
Willow | 455 | 415-505 |
Hazelnut | 435 | 425-455 |
Fir | 415 | 345-600 |
Bamboo | 400 | 390-405 |
Poplar | 400 | 395-585 |
Important! The table shows the data taking into account the moisture content of wood in 12%. For example, the specific gravity of pine wood is 520 kg / m 3 .
What does the indicator depend on
The density of wood is determined by the breed. Based on this, calculate the average generally accepted specific gravity of wood, which is obtained as a result of repeated practical studies. In the course of a series of experiments with one breed, one can obtain structural density indices that are different from each other. In fact, in one table presented above, data on the density of tree species collected from different sources are collected, which indicates the variability of the absolute and relative indicators of the specific gravity of wood.
Wood density groups
It is generally accepted to calculate the specific gravity of wood of different species with a moisture content not exceeding 12%. This is a normative indicator, according to which wood is divided into three density groups:
- Low density (up to 545 kg / m 3 ). This category includes: spruce, pine, fir, cedar, juniper, poplar, linden, willow, aspen, alder (white and black), sowing chestnut, walnut (white, gray, Manchurian), Amur velvet.
- Medium-density (555-745 kg / m 3 ) species are represented by: larch, yew, birch (dangling, fluffy, black, yellow), beech (Eastern, European), elm, pear, oak, maple, hazel, walnut, plane tree, mountain ash, persimmon, apple tree, ash (ordinary, Manchurian).
- High-density (over 755 kg / m 3 ), including: acacia, iron birch, hornbeam, chestnut oak, iron tree, boxwood, pistachio tree, hop-horn.
The figure below shows a tree hardness chart . Values are given in coefficients.
How rock density is related to wood combustibility
The calorific value of firewood (heating energy value) is determined based on the main indicator - the proportion of wood. This is explained by a direct relationship: the higher the density of the rock structure, the higher the percentage of combustible matter contained in it and the better the fuel burns.
Density indicators are actively used in construction, selecting material for building a house, roof truss system, designing furniture, purchasing fuel for production.
It is unrealistic to do without wood processing products. Having abandoned lumber, humanity will not be able to exist fully. Therefore, studies conducted with wood are of no small importance, because thanks to this, engineers are able to construct durable residential buildings, produce durable and reliable furniture, and purchase high-quality raw materials for heating enterprises.