What tree is the strongest. Tree species. Hard conifers - larch and juniper

In this article, we will talk about unique hardwoods that are rarely found in nature and even less often come across in the form of products. You will learn about the strength and hardness of these rocks and where they are used. The article also contains comparative characteristic wood properties.

Continuing the theme of exotic woods, we will talk about a material that until recently was not available in Russia. The development of trade and transport made it possible to deliver exclusive products and furniture from the wood of the tropics, Africa and Oceania. Over time, these products have gained wide popularity not only as a luxury or exotic item, but also as a practical item. construction material with unique properties.

Hornbeam

The uniqueness of this type of wood lies in the fact that it is popular not so much as lumber, but in its living form. He is the only one of the above, which can be found on the free market.

The hornbeam grows in the Northern Hemisphere and is most common in China. Its structure resembles a bush, but it grows very slowly. It is thanks to this combination - bushiness and slow growth - that live hornbeam has become a favorite material for masters of gardening art and lovers of green hedges. The green cap of the tree keeps its shape up to 15 days after shearing, and the density of the branches allows you to create opaque living sculptures. The hornbeam gained great love in Japan, where the art of bonsai is popular - decorative species are specially bred for this.

The mechanical properties of hornbeam wood are at least impressive:

Density - 750 kg / m 3.
The hardness of the cross section is 83.5 MPa.
Brinell hardness - 3.5 kgf / mm 2.

These figures are an order of magnitude higher than those of the average (reference) oak. However, such properties have their price, and it lies in the shortcomings of hornbeam lumber:

High volumetric shrinkage. The material shrinks and cracks as it dries.
Difficult processing. Due to the peculiarities in the structure of the fibers, the hornbeam does not lend itself well to conventional grinding.
It dries slowly and is difficult to process with a tool.

The undoubted advantage of such lumber is a beautiful sinuous structure, sometimes of different colors (dark brown and yellowish). From the hornbeam they make piece and artistic products - billiard cues, musical instruments, souvenirs and some details of machine tools.

boxwood

This evergreen shrub has other names - green tree, shamshit, bux, bukshpan, gevan. Such an abundance of different names is explained by the antiquity of the breed and the breadth of the habitat - Central Africa (Madagascar), Central America (Cuba, North Mexico), Eurasia.

Like the hornbeam, boxwood has a lush, dense crown that grows slowly and holds its shape perfectly. In a living form, it is used in landscaping and park architecture.

Boxwood has been used since ancient times as medicine in the preparation of decoctions and infusions. Today, this is not done due to the high toxicity and poisonousness of all parts of the plant. The leaves are especially poisonous.

Mechanical properties of wood:

Density from 830 kg/m 3 (dried) to 1300 kg/m 3 (freshly cut).
The hardness of the cross section is 115.5 MPa.
Brinell hardness - 3.9 kg / mm 2.

The trunk of boxwood does not have a core, so lumber is widely used in artistic cutting, decorative sculpture and woodcuts. The felling of this tree is strictly controlled throughout the world, because, due to its exceptional properties, it was so widely used in printing in the early 19th century that it was almost completely destroyed. The high cost of wood makes it unprofitable and irrelevant to produce joinery from it.

WIKIPEDIA: The range of boxwoods in Russia is constantly decreasing due to logging. Especially large areas of boxwood relic forests were damaged in the fall of 2009 during the construction of the Adler-Krasnaya Polyana Olympic road. Several thousand trunks were uprooted and buried. Colchis boxwood is listed in the Red Book of the Russian Federation.

iron tree

Under this name, several dozen species of trees are combined, which grow mainly in Asian countries, Oceania and Australia. They are distinguished from all other trees by one feature - a density of more than 1000 kg / m, i.e., more than the density of water.

Parrotia Persian(iron ore, demir-agach, ambur) - named after the naturalist Ivan Parrot. It grows in the relict forests of Azerbaijan. Beautiful appearance and frost tolerance have made it a popular ornamental plant in Europe. Due to its rarity, the wood has not been classified, but its exceptional strength is known for certain. Local residents have long made ax handles, floor boards and responsible carpentry from it. The cost of parrotia is several times higher than for wood with the same properties - relict forests are under the protection of the state and UNESCO.

Quebracho or mahogany- grows in the northern regions of Brazil and Argentina. Its name comes from a combination of the words quiebra-hacha (Spanish), which means "breaking an ax" in translation. Red quebracho is relatively common in Russia, so there is data on its trials:

Density - 1200 kg / m 3.
The hardness of the cross section is 81.5 MPa.
Brinell hardness - 3.2 kg / mm 2.

In addition to the “eternal” material for furniture in quebracho wood, tannin is of great value, which gives it a red tint. An extract is obtained from the bark and wood, which is used to treat asthma, heart and circulatory diseases.

A less common species - white quebracho - has a lower density (850 kg / m 3) and is rarely used in Eurasia due to the presence of cheaper local analogues.

Buckout or Guaiac Tree — national symbol Jamaica (flower). Grows in the Caribbean islands South America and India. Its wood is so dense that it does not have the ability to split, and ranges from 1200 to 1450 kg / m 3. Backout resin is valuable for medicine - based on it, they make medications and chemical reagents.

Exceptional hardness and high natural oiliness give the wood durability and good mechanical properties. Backout's "track record" is the most impressive of all:

Details of the oldest sailing ships that have survived to this day.
Detail of grandfather clock with wooden mechanism.
Bearings (!) in the steering and screw mechanisms of diesel submarines and the turbine of the power plant (!) Conowingo (Conowingo) on the Susquehanna River.
Bowling balls, croquet sticks and clubs for British policemen.

The list of applications makes it clear that in some cases, backout may well replace iron.

Acquiring materials from the trees described above is extremely difficult for two reasons. First, most of them grow in the tropics or remote (from Russia) regions of the world. The second is that almost all of them are protected because of their rarity. Therefore, the acquisition of this valuable material is a separate task that should be planned for the long term.

However, there is a more popular and acceptable solution - the use of imitation of a given breed from a more common and cheaper material. For example, a larch parquet board can be finished with a thin layer of querbach and look like querbach after installation. This approach brings the desired result, reasonably saving money and natural resources.

Acacia is the hardest of the trees growing in Russia. Its color is yellow or olive green, the layers are straight and sharply visible. It is processed well only in its raw form, while in the dry it is difficult to process with cutting tools; does not crack and does not warp; remarkably resistant to friction; almost insensitive to atmospheric influences; under the influence of light, the acacia changes its color somewhat and becomes very beautiful with time.

Durable, hard and at the same time elastic acacia wood is used by furniture makers. They also make excellent veneer for facing MDF boards or products made from low-value wood species.

Acacia wood is an excellent material for floor coverings. Their service life is comparable to ash or larch parquet. In addition, excellent doors are made from it, which are stronger than oak ones (an 80 mm thick acacia door cannot be shot from a PM pistol from a distance of 10 m).

Thoroughly dried and varnished parts retain their shape and dimensions better in dry rooms. Acacia wood is ideal for glued and screwed joints. Both organic solvent-based paints and water-soluble varnishes and paints are equally well suited for finishing products from it, but the natural texture and color always look better.

One of the difficulties in working with acacia is due to the fact that it is initially prone to cracking, so it needs gentle drying modes, which increases the time. Another difficulty is that acacia has a multidirectional texture - the fibers in the wood are located towards each other, like mahogany - which makes processing much more difficult. But the result is worth it. Acacia wood is a sophisticated interior material that creates a beautiful contrasting backdrop for dark furniture.

Birch is the most common finishing material in the northern part and partly in central Russia. Its wood is the lightest, homogeneous, fine-grained, dense, hard, well cut. It sharpens, pricks, saws and plans excellently. It is convenient to use it for small crafts, since birch reacts to temperature and humidity and can warp in large products. Dries slowly and hard; does not rot quickly, especially in a dry place, but is highly susceptible to wormholes. A very beautiful veneer is cut from the smelting. The best birch tree gives in the period of 40-50 years, and then the good qualities progressively decrease. Old wood is easily identified by its darker color.

Beech (red beech) - In Central Europe, this is the most common type of wood. But beech wood growing in the mountains is of better quality. In some conditions, especially in underwater structures, it is not much inferior in strength to oak. Beech is a champion among other common ornamental wood species, especially for being well planed, processed on a lathe, and bent in a steamed state (in this it is second only to walnut). Resistant to splitting, but not resistant to cracking. It is an excellent ornamental material for interior decoration, it cuts very well, although dry wood crumbles and pricks in fine carving across the fibers. In everyday life, it is used to make drawing rulers and squares, shoe lasts, parquet, furniture (especially cribs and playpens). These end-of-life items can be used for carving. Beech is not suitable for house carving, as it is extremely hygroscopic and warps when wet, prone to wormholes and decay. To prevent the attack of worms, finished beech products are smoked or steamed. To make the tree less warped, it is cut down in the middle of summer, and then, after a year, it is sawn into boards, which are placed in water and kept in it for several months.

The color of the wood is reddish-brown with many large and darker spangles; in old age it darkens and turns into brown, and therefore is not used at all for elegant products. Steam-treated beech bends easily. This feature is used in the furniture industry in the manufacture of Viennese chairs - the famous bent Viennese furniture, for which there is no more suitable wood. But even in this case, the beech is etched and stained in order to change the nondescriptness of natural wood. When steamed, the beech easily bends, and after drying it retains its shape for a long time. The rawer the tree, the easier it is to process; it is very poorly polished, but it takes color well and imitates walnut especially well.

White beech or hornbeam, has a whitish-gray wood, very hard and strong, with lighter sheen on a smoothly finished surface. Annual layers in the cross section have an irregular wavy shape. Sapwood is as hard as seasoned wood. While the wood is damp, it warps a lot; but after thorough drying almost completely does not change its shape from atmospheric influences; as it dries, the hardness of the hornbeam increases so much that the hornbeam requires the sharpest tools. With cutting tools, the hornbeam is almost equally processed both along the fiber and from the end.

Thanks to these qualities, the hornbeam is used in carpentry and modeling.

In the carpentry and furniture business, the hornbeam has no use, since it is ugly in appearance and too heavy, and besides, it is very poorly polished. The hornbeam takes color perfectly, and therefore it is sometimes used to fake ebony. This is most often done by turners, since the hornbeam sharpens very easily and well.

Cherry - in Russia it is common in the south and in the middle lane. The wood is dense, strong and elastic, but it is well processed and cut in all directions. In terms of structure, an adult tree is surprisingly elegant and decorative. When dry, the cherry tree is strong and hard, easily pricked and planed. As a finishing material, cherry is one of the most valuable and decorative species, and since the early Middle Ages (according to interior items that have come down to us) it has been used to decorate works of art and architecture. Musical instruments, stairs were made and are still being made from it, the famous Turkish chibouks are made from some varieties of cherries, growths and root nodes are valued by turners. It is used exclusively for the manufacture of expensive furniture. Cherry furniture is distinguished by a special aristocracy, even relatively recently created items look like rare antiques. It accepts polish and paint perfectly, it is especially well painted under mahogany. In house carving, the use of cherry is limited, in particular, small size blanks. But using the decorative texture of cherry in small panels or rosettes is perhaps tempting.

Elm (elm, birch bark, elm) - varieties of the same tree species. The most common species is the common broadleaf elm, distinguished by its heavy, light wood that darkens with age. The wood of old trees is dirty pink, dotted with many veins and dashes. Despite the distinctness of annual layers, the tree is very dense and slightly porous. It does not crack at all and warps very little. Resilience and flexibility are remarkable; elm is used to make wheel hubs and rims, sleigh skids, large-sized wooden screws, as well as all kinds of products that require endurance during shocks and impacts, but do not require a smooth surface and elegance of finish. The ability of the elm to bend (and taking into account its light tone) is used to make curved contours and framing in decorative panels, house carving ornaments. All trees of this family, due to viscosity and fine fiber, are pricked, planed, smoothed and polished extremely poorly. As a result, they are rarely used in furniture business.

Hornbeam - wood is light, grayish-white, shiny, heavy and hard. It cracks a lot and warps when it dries. The extraordinary hardness of the hornbeam, resistance to abrasion and splitting from impact (only white locust is ahead of it in this). Due to good staining with black dyes, high strength and hardness, hornbeam wood is used as an imitation of ebony. To avoid deformation and cracking, it requires a long and careful drying.

Pear - wood is obtained mainly from the game, due to the thickness and height of the trunk forest plant, which the garden pear usually does not reach, although the latter has wood no worse. The color of young wood is yellow-white, and old wood is brownish. The structure of the wood is dense, without noticeable pores and annual layers. The pear is planed and cut in all directions equally well. From soaking in water and then slow drying, the pear tree noticeably hardens and turns brown. In the modeling business, it is used to make expensive carvings, and in the manufacture of expensive furniture, it is used to fake ebony, which the pear is much superior in strength. The pear is excellently polished. Its only drawback is its propensity for wormholes.

Oak is a hard and strong tree of brown-yellow color with strong noticeable annual stratifications, in the spring part of which there are many pores. A special characteristic of oak can be frequent and thick core rays. The wood of young trees is hard, flexible and greyish-brown in color. In older trees, the wood is yellower and more brittle. There are many varieties of oak, but we will divide them only into two groups: The first includes varieties that grow in the south and differ in appearance in that their acorns sit directly on the branches, and also in that the leaves turn yellow in autumn, but only fall from the tree. in winter or even in spring, when young ones appear. This variety is called winter oak and its wood is valued more than the other group. It goes mainly for parquets and characteristic wooden furniture, decorated with carvings. The best wood is given by oak in the period of 80-150 years of age, taken from the black forest, i.e. from dense forests. Pure oak forests do not produce good trees, as their trunks are squat, thick and gnarled.

Another group of oaks is known under the name of spring oaks and differs mainly in that their acorns sit on long petioles, which winter oaks do not have. The wood of spring oaks is somewhat more viscous, knotty and grayer - in general, it is lower in quality than the wood of the previous group.

Planed and sawn oak is quite difficult, it is pricked easily, and the polish takes very badly because of the sponginess.

Oak is especially resistant to water, where it takes on a completely black color, which raises its value as a material for expensive furniture.

Spruce - in appearance it is somewhat similar to a pine tree, but differs from it in greater softness, pallor of annual layers and a large number of small knots. Spruce does not differ in especially good qualities, and it owes its wide distribution to its cheapness and similarity to pine.

In products that are directly affected by atmospheric changes, spruce quickly rots. It warps a little and this is almost her only good quality. Spruce is planed, sawn and pricked easily.

Karagach (elm, elm, birch bark) - varieties of the same tree species. The most common species is the common broadleaf elm, distinguished by its heavy, light wood that darkens with age. The wood of old trees is dirty pink, dotted with many veins and dashes. Despite the distinctness of annual layers, the tree is very dense and slightly porous. It does not crack at all and warps very little. Resilience and flexibility are remarkable; elm is used to make wheel hubs and rims, sleigh skids, large-sized wooden screws, as well as all kinds of products that require endurance during shocks and impacts, but do not require a smooth surface and elegance of finish. The ability of the elm to bend (and taking into account its light tone) is used to make curved contours and framing in decorative panels, house carving ornaments. All trees of this family, due to viscosity and fine fiber, are pricked, planed, smoothed and polished extremely poorly. As a result, they are rarely used in furniture business.

Chestnut (wild / horse) - gives a very beautiful, almost completely white, but, unfortunately, a very soft tree. The wood of old trees loses its whiteness and turns yellow or red. Chestnut is processed very easily, but soon rots and loses strength. It also paints well and at the same time it lasts longer from damage. Due to the above reasons, he plays a role only in haberdashery and amateur art works.

An edible chestnut gives a tree completely opposite in properties to a wild chestnut. It is hard, brown (similar in color to oak), very durable, not warping or cracking. Polishing takes very well. His appearance is not particularly attractive, and therefore is rarely found on sale.

Cedar is a kind of pine (Siberian pine). The tree is soft, prickly, pinkish-brown in color, with a pleasant smell. Since ancient times, it has been used to make furniture, in construction, as well as pens and pencils - sometimes called pencil - does not warp and is not at all susceptible to wormholes.

Maple - gives a whitish wood with many small sparkles, giving the tree a silky look. The tree is dense, dense, of medium hardness and almost never cross-layered, as a result of which it is pricked and planed perfectly. If we add to the above that maple warps a little and resists moisture well, it becomes clear why it is so highly valued by carpenters. Expensive models of carved jewelry are made from it. Maple perceives polish very well; it is also well painted in different colors, therefore it is used to fake acacia and boxwood, to which it is close in its structure (but not in density).

Mahogany (mahogany, amaranth) is the most common and well-known of all tropical trees, under the name of which the most diverse and heterogeneous breeds are sold, having a common color and partly the appearance of texture. It is easy to process, and although redwood is quite soft, it still belongs to the category of the most desirable joinery materials. The reason for this is not so much in its beauty, but in the persistent resistance to atmospheric influences and the perfect immutability of form. Therefore, it goes to the manufacture of expensive furniture, grand pianos and pianos.

In Russia, there is not even half of all varieties and varieties of mahogany, so it is pointless to present the details of its merchandising. Most often we have a bad yellow-orange variety, known as a sugar, or chest, tree. Its smell is weak and rather pleasant for humans, disastrous for insects. Therefore, the best chests and wardrobes are made from sugar wood. This tree is called sugar because American sugar was transported in boxes from it, and these boxes were then sold as carpentry material.

Linden - gives light, white wood with barely noticeable annual layers. Works well, especially with cutting tools. It warps very little, is not afraid of dampness, but, unfortunately, is prone to a wormhole. The best tree gives the southern linden; from it are prepared mainly foundry models and all different products under gilding.

Little is used in turning, except for handicrafts and children's toys. From linden, characteristic furniture under white colored polish is good. Linden is painted very poorly, as it is distinguished by remarkable impermeability. Honey, for example, flows through the walls of any wooden vessel - one linden does not let it through.

Larch - belongs to the category of the most best trees in both construction and carpentry. The wood is reddish in color and is remarkably durable. It is much more stable than oak and is equally hardy both in water and in air. The reason for this should be sought in a large amount of resin. Larch is processed very smoothly and well; almost does not warp and is not subject to a wormhole.

Juniper - grows everywhere in the middle lane, but is very rarely tree-like, and its ordinary shrub never produces thick pieces of wood suitable for larger products. Young plants produce almost white, and old ones whitish-yellow, not too hard, very thin-layered, dense and flexible with wavy growth rings and very hardy. The rare properties of juniper wood include its pleasant sandarach smell, which is preserved in products that have lain in the ground for thousands of years.

Alder - the wood of this tree is quite heavy and resilient; layers are hardly noticeable, the structure is dense; color dirty pink or dirty orange. Yellow or brown oblong spots are a sign of decay or deterioration; under water and in dampness, the tree is very strong and resistant, in a dry place it soon rots and worms. It lends itself to any manual processing very well, it also polishes well and takes on all kinds of colors, it is suitable for making models of various products, as it is easily cut. In the count's estates, there were always sets or individual pieces of furniture made of alder.

Common walnut (Persian) - grows in the Caucasus and is brought to us in large quantities. Young trees give soft and white wood, while old trees give the well-known dark brown, dotted with darker veins, sometimes taking on a completely dark color. The older the tree, the more beautiful and better its wood. The walnut is processed well and perfectly accepts polishing and coloring. Lighter wood is sometimes successfully imitated by mahogany.

Aspen (trembling poplar) is a very common tree in Russian forests, which reaches a solid size and sometimes lives up to 150 years. The wood is white, soft, easily pricked and cut, but strongly warped and completely inexpressive, and therefore is practically not used in carpentry. The tree often rots on the vine, but dry and seasoned aspen becomes unusually resistant to decay even in dampness. Ploughshares were made from it, with which they covered the domes of wooden churches with their unique silvery tint, and benches and shelves in the Russian bath are made from it.

Rosewood - a violet tree, or jacaranda is brought from the hot countries of South America and East India, is valued as an excellent material for the manufacture of expensive furniture and items. Its wood is very hard, dense, fine-fibered and porous; its color is difficult to determine due to the various shades that make it up. In most cases, dominated Brown color with a violet tint, mottled with lighter veins, forming a beautiful pattern. Without careful polishing, which is difficult to achieve, over time, rosewood darkens to black. Worn with a cloth, it emits a pleasant smell, reminiscent of the aroma of Parma violets.

In strength, rosewood is inferior to mahogany, and surpasses it in beauty; in expensive finishes, it is used in conjunction with metal, which emphasizes the natural beauty of wood.

Pine is a well-known yellow-red or pale yellow wood for its wide use, not particularly hard, but easy to work, resistant and durable in various products. In dense northern forests, pine trunks are quite long and are distinguished by remarkable straightness and straightness; both of these qualities, together with causticity, are very important for construction work.

Pine is planed along very easily, but across it is difficult and not smooth; sawed well, the glue holds firmly.

It is used for all kinds of crafts, which would be very difficult to list. Cheap furniture, doors, window frames are prepared from it, and absolutely everything is built in Rus' - from a barn to exhibition pavilions.

Sweet cherry - in appearance it is very similar to cherry, but reaches such a thickness that it can be sawn into boards. Its wood is denser and harder than that of cherry, and therefore its use is preferable. This tree is highly susceptible to wormholes. The smeltings have a beautiful graininess of the fibers.

Ash - reaches, under favorable conditions, a gigantic growth and a thickness of up to five feet. Its wood is not particularly beautiful, yellowish in color with alternating light and dark stripes. When finishing, annual layers are strongly manifested due to the many pores clogged during grinding and polishing. Ash is quite hard, dense and heavy, and most importantly resilient; when dry, it is quite strong, especially after steam drying. But when raw, it is easily wormhole-prone and very sensitive to atmospheric changes.

In carpentry, ash is used to make doors, furniture for anterooms and shops. It is not particularly used in turning, as products made from it have an awkward and heavy appearance. Ash smeltings are highly valued by turners, which are distinguished by their hardness, density, beautiful shades and fiber pattern.

In the fields of construction and production, traditional consumables are being replaced by high-tech plastics in various designs. They are distinguished by high technical and physical qualities, which allows them to confidently replace both wood and even metal. However, wood raw materials have many advantages due to the low cost of purchase and environmental friendliness. Strength is considered the weak point of this material. To increase this indicator, manufacturers use special processing methods to increase rigidity, density and, in general, resistance to mechanical damage. However, solid wood species initially have these properties, often eliminating the need for special heat treatments.

Hardwood Features

Typically, the quality of such rocks is evaluated by three indicators - density, Brinell hardness and cross-cut stiffness. On average, the density of such wood is about 1200-1400 kg/m 3 . As for the hardness according to Brinell, this value can reach 3.5 kgf / mm 2, and the rigidity of the transverse cut is 80 MPa. Again, these figures are typical for trees familiar to Russian conditions, and exotic species may have significantly superior characteristics. What types of wood are hardwoods in the temperate zone? Usually isolated oak, beech, ash and some types of hornbeam. It is important to consider that, along with positive quality in the form of hardness, such trees also differ in negative properties. It has already been said that in order to improve the performance, lumber can be subjected to additional processing. Sometimes for special physical characteristics solid wood is subjected to similar operations. And here a serious problem manifests itself, since many rocks, due to their high density, cannot stand the processes of grinding, impregnation, and especially drying. Often cracks, chips and other manifestations of structural deformation are formed.

Hardwood classifications

Allocate species that grow in the temperate zone, and exotic trees. There is also a classification into deciduous and coniferous species. Although most hardwoods are still deciduous, among the needles there are also varieties with increased density and stiffness characteristics. As for breeds temperate zone, then they include maple, boxwood, briar and the mentioned hornbeam. Coniferous hardwoods are also the most common here. Which of them has the most pronounced indicators of hardness? In this case, larch, yew, juniper and lawson deserve attention. There are also hardwoods among the usual fruit trees - in this category forest apple, oxalis, pear, mountain ash and some types of walnut stand out. As for exotic rocks, they demonstrate the highest rates of hardness and density. Here, red and lemon eucalyptus, etc., are of particular interest. Now it is worth considering in more detail the hardest tree species.

Red tree

In Russia, this breed is the most popular, as it can be purchased on a free sale. This is a tropical tree, which is characterized by high hardness, as well as the original texture on the cut. Freshly sawn wood has a yellowish-red hue, but over time it is replaced by darker tones, which gives the material nobility. Accordingly, the consumer appreciates not only the technical, but also the decorative properties of this tree. It should be noted that from the point of view of pronounced decorative qualities, backout and boxwood also belong to hardwoods. Moreover, these rocks are used not only as finishing materials, but can also replace individual decorative details in jewelry and technical devices. But mahogany is also distinguished by ease of machining. The density of this rock is not so high compared to many solid materials of tropical origin, so this raw material is in great demand in furniture factories.

iron tree

If heavy-duty plastics can replace iron due to their strength, then this rock is not only able to take the place of an element resistant to mechanical stress in some areas, but at the same time meet increased requirements in terms of environmental resistance. The concept of an iron tree includes a whole group of species that mainly grow in the countries of the Asian region and in Australia. The classic representative of the group is the Persian parrotia. This species is common in relic forests, where local residents have been making handles for knives and axes from it since ancient times. Today, the "iron" wood of hardwoods is under the protection of UNESCO. This breed, in particular, has an aesthetic value, which causes great interest in it from the market.

Merbau

This is not the hardest, but in terms of other operational qualities, one might say, the most practical breed. Previously used in the construction of marine vessels. This is due to the fact that the material is resistant to moisture and also does not dry out. Therefore, merbau can be stored for a long time, after which it can be subjected to heat treatments and used in construction. As already noted, hardwood trees, like hornbeam or beech, practically do not tolerate additional processing. But merbau steadfastly endures traditional methods of influence in order to improve individual performance.

white locust

The hardest rock in Russia, which is valued not only for its strength, but also for its resistance to biological destruction processes. In addition, this type of acacia is well polished and does not crack during long-term operation. Subject to preventive treatment measures, wood is also not subjected to minor mechanical damage. By the way, by technical specifications this species outperforms hardwoods such as oak and ash.

Lignum vitae

The hardness index of this tree is one of the highest in the world. Suffice it to say that the material optimally copes with its tasks when used in the form of bearings, bushings and brackets. In the navy, the wood of this species was often used as deck material. But as lumber, backout is valued for other reasons. It does not lend itself to deforming processes under the influence of third-party negative factors. These can be both chemical and physical influences that do not have a destructive effect on the structure. There are other hardwoods that also show resistance to extreme loads. But the unique quality of the backout is a balanced combination large mass and density.

The use of hardwood

Most of this material is used in construction. Wood in one form or another can be used as a basis for structures, and as a finish. Separate breeds are also used in the fields of mechanical engineering and instrumentation. Of these, separate functional elements are made with the expectation of long-term use - and these can be both temporary consumables and durable parts of structures. These are the main, but not all, areas in which high-strength wood species are used. Soft, hard rocks, as well as those with average density values, can also be used for medical purposes. In this case, hardness is not so important. The fact is that many exotic breeds contain resins that are unique in their qualities. The preparation of therapeutic mixtures for internal and external use, in particular, allows you to deal with diseases of the joints, respiratory organs, etc.

Conclusion

Manufacturers of building materials are well aware of the rule that the improvement of one technical and operational property almost always entails the minimization of other qualities. In part, this law also applies to hardwoods, which, according to some characteristics, lose to softwoods. The processes of biological destruction, physical deformation, as well as texture distortion are the main disadvantages of soft rocks used in the long term. But on the other hand, such wood has the advantage of being susceptible to additional treatments. Of course, there are exceptions in both categories, but the soft structure, due to its low density, is still more inclined to form new properties artificially.

Not everyone knows that oak is not the hardest wood species. Many other trees are denser and have their own unique properties and textures. From this article you will learn what hardwoods exist, what features they have. In the production of furniture, various household products and materials, only hardwoods are often used, since they are very reliable and durable.

Solid wood is excellent at resisting the effects of other, denser bodies, such as metal objects. The hardness index has importance when choosing building materials. Floor boards and other wood raw materials must be hard enough to withstand heavy loads. The high density material is difficult to work with, but hardwood is very wear resistant, making it an expensive material.

The tree is tested for strength at the moment when processing is carried out using self-tapping screws, drills and nails.

Depending on how the impact on the board is carried out, the strength indicator may vary. The strongest products withstand the load with different parties: along the annual rings of the tree, radially, from the end and frontally.

Important! Such a value as an indicator of the hardness of a tree is formed according to various parameters and in a certain time period. The depth of the imprint left by a foreign object on a tree matters, the pressure force.

The generally accepted option for determining the degree of strength and strength of a tree is the Brinell method. This parameter is especially important when sampling. On a dense tree there are no traces of furniture legs, heels.

When measuring the strength of a tree using the Brinell method, it should be taken into account that, on average, a ball with a diameter of 10 mm enters the tree with great force and an indentation occurs with a mass of 100 kg. As a result of the calculations, the damage caused by such an indentation is determined and the strength parameter is highlighted. All damages are taken into account: dents, cracks, chips. For durable wood, the Brinell index is higher. In general tables, you can find a value expressed in MPa. So, 10 MPa is 1 HB, which is equal to 10 N / mm².

What determines the hardness of wood

Density values are different for each type of wood, but there are a number of common factors.

Factors affecting the degree of wood hardness:

the age of the breed, the older the wood, the higher the strength characteristics it has. A young tree is wet, while an old one dries up and becomes stronger;
climate and geography of growth. In cold climates, trees are stronger because they grow extremely slowly;
the way the tree was sawn. There are certain techniques for enhancing sawing strength;
the area in which the trunk is cut. The density of the bark is always higher than that of the core of the tree.

Advantages and disadvantages of hardwood

Despite the fact that durable boards are considered the most preferable in construction and during construction, both positive and negative points can be distinguished. Advantages of hardwoods:

no additional impregnation of wood is required;
boards are wear-resistant and durable;
wood and furniture from it has a beautiful, unique structure.

Minuses:

the complexity of processing boards;
high price;
not suitable for all types of furniture and floors.

Hardwoods are unpretentious and practically do not need additional care, however, it may be difficult to fix furniture from solid wood on the wall and mending if needed.

The degree of hardness of trees characteristic of Russia

The strongest and strongest tree species in Russia are boxwood, acacia and dogwood, as well as hornbeam. These breeds are used in the design of handrails, and are made different types parquet. This material is affordable, but not inferior in quality to more expensive materials. These types of trees are the most widely used. Other species, including exotic ones such as sucupira, hickory and kumaru, are also used in the production of parquet boards.

Durable wood species are used not only in standard cases, for the manufacture of floors and furniture, but also in the production of souvenirs, working parts for various equipment, such as machine tools. IN Southern countries there is a huge number of trees with strong and resistant wood, such as jatoba. This tree grows in South and Central America, in the tropical forest. Strength on the Brinell scale - 7 points. Jatoba blanks have a light shade and a grayish coating, however, the core is colored in rich orange or red. After the tree is cut down, it gradually darkens. A week later, a permanent color is acquired - brick red. This tree grows rapidly and reaches up to 40 meters in height.

Amazonian Yarra has a very high strength, its indicator is 6 points. The tree grows in South America. The heartwood is a rich plum or deep red, while the sapwood is brownish or yellowish. When sawing, jarrah blanks darken when exposed to moisture. The boards are flexible, but sawing them and achieving a perfectly even shape is difficult.

tree growing in tropical forests West Africa reaches a height of 60 meters. Mutania is very strong and has an indicator of 5 points. Mutania blanks are brown in color, reminiscent of Walnut. The tree is unique due to the appearance of purple "rays" when sawn.

On the territory of Asia Minor and Europe, European walnut grows on the south side. On the scale of hardness, this tree reaches a score of 5 points. Walnut wood is very expensive and is highly valued by true lovers of natural, high-quality furniture. The structure of the boards is very unusual - you can see a wavy pattern, while the fibers are parallel and even.

The hardness index for Merbau wood reaches 4.9 points, which is not the largest, but not the smallest either. natural area, in which merbau grows best - Papua, New Guinea, Asia. The average height of an adult merbau is 30 meters. Due to the high density, the tree weighs a lot, on average - up to 800 kg per cubic meter. The natural shade of wood is yellow or light orange. Over time, after cutting and processing, the boards darken, become brownish, with a bronze or silver tint.

For those who prefer pine needles, larch would be an ideal option. In terms of density, it does not exceed other trees, according to the Brinell scale, larch has only 2.6 points, however, it is wear-resistant. The color of the boards is dark red at the core and along the edges with a yellowish tint. Larch is used in the construction of houses, they can withstand a long time even in the wettest regions. The viscosity of wood is high, so processing is extremely slow. When moisture gets in, wood becomes stronger, and if it is deliberately soaked, you can get a strength indicator comparable to stone.

In the table you can see the hardness indicators of different tree species.

What types of wood did you use in the decoration, and which boards seemed the most durable, wear-resistant?

Hornbeam

The uniqueness of this type of wood lies in the fact that it is popular not so much as lumber, but in its living form. He is the only one of the above, which can be found on the free market.

The mechanical properties of hornbeam wood are at least impressive:

Density - 750 kg / m 3.
The hardness of the cross section is 83.5 MPa.
Brinell hardness - 3.5 kgf / mm 2.

These figures are an order of magnitude higher than those of the average (reference) oak. However, such properties have their price, and it lies in the shortcomings of hornbeam lumber:

High volumetric shrinkage. The material shrinks and cracks as it dries.
Difficult processing. Due to the peculiarities in the structure of the fibers, the hornbeam does not lend itself well to conventional grinding.
It dries slowly and is difficult to process with a tool.

boxwood

Like the hornbeam, boxwood has a lush, dense crown that grows slowly and holds its shape perfectly. In a living form, it is used in landscaping and park architecture.

Boxwood has been used since ancient times as a medicine in the preparation of decoctions and infusions. Today, this is not done due to the high toxicity and poisonousness of all parts of the plant. The leaves are especially poisonous.

Mechanical properties of wood:

Density from 830 kg/m 3 (dried) to 1300 kg/m 3 (freshly cut).
The hardness of the cross section is 115.5 MPa.
Brinell hardness - 3.9 kg / mm 2.

iron tree

Parrotia Persian(iron ore, demir-agach, ambur) - named after the naturalist Ivan Parrot. It grows in the relict forests of Azerbaijan. Beautiful appearance and resistance to frost have made it a popular ornamental plant in Europe. Due to its rarity, the wood has not been classified, but its exceptional strength is known for certain. Local residents have long made ax handles, floor boards and responsible carpentry from it. The cost of parrotia is several times higher than for wood with the same properties - relict forests are under the protection of the state and UNESCO.

Density - 1200 kg / m 3.
The hardness of the cross section is 81.5 MPa.
Brinell hardness - 3.2 kg / mm 2.

A less common species - white quebracho - has a lower density (850 kg / m 3) and is rarely used in Eurasia due to the presence of cheaper local analogues.

Buckout or Guaiac Tree- the national symbol of Jamaica (flower). It grows in the Caribbean, South America and India. Its wood is so dense that it does not have the ability to split, and ranges from 1200 to 1450 kg / m 3. Backout resin is valuable for medicine - medicines and chemical reagents are made on its basis.

Exceptional hardness and high natural oiliness give the wood durability and good mechanical properties. Backout's "track record" is the most impressive of all:

Details of the oldest sailing ships that have survived to this day.
Detail of grandfather clock with wooden mechanism.
Bearings (!) in the steering and screw mechanisms of diesel submarines and the turbine of the power plant (!) Conowingo (Conowingo) on the Susquehanna River.
Bowling balls, croquet sticks and clubs for British policemen.

The list of applications makes it clear that in some cases, backout may well replace iron.