Materials scientists have made wood twenty-three times harder and made a knife from it

Wood was considered one of the earliest and most accessible materials for humans. The first objects, the first weapons were created from it and houses were built. In those days, people did not yet know about strength and hardness. But this did not stop them from paying attention to the different strengths of wood. Some species are nicknamed iron trees for these properties.

In our world, methods for determining hardness have long been developed, for example, through the Rockwell and Brinell methods. They consist of pressing the sample that is being tested with a Brinell ball and a Rockwell diamond. This is done with the same effort. The resulting depth is then measured. People tested different types of wood in this way, thereby determining the hardest types of wood.

Jatoba

The hardness is 7.0 Brinell. Quite often, jatoba is called South American or Brazilian cherry. However, she is far from being related to Cherry. The height of the tree is up to 40 meters, and it also has a wide crown. Young shoots are covered with brown hairs. As for the leaves, they consist of two broadly crescent-shaped, pointed leaves up to 7.5 centimeters long.

What you need to know about wood species

There are a lot of trees growing in nature. Today there are many types of wood, which, naturally, have different properties and their own characteristics.

In order not to make a mistake in choosing a breed specifically for your operational tasks, you need to know its general characteristics and scope of application. We'll talk about this today.

Sapwood and heartwood

The structure of any tree, regardless of its species, consists of core and sapwood. The core is the inner, central part of the trunk, consisting of dead wood. Surrounding the core is a layer of living cells called sapwood.

Tree species are generally divided into deciduous and coniferous, as well as:

• sapwood: the core of their trunk does not die (linden, alder, maple, birch);
• sound: the core has a dark shade (oak, ash, pine);
• mature wood: the shade of the core is identical to the color of the sapwood (spruce, aspen).

The color of wood depends not only on the species, but also on other equally important factors, for example, the growth rate of the tree and its age. The heartwood is usually always darker than the sapwood (with the exception of mature wood species).

Hardness

It is quite natural that the harder the tree, the greater wear resistance, practicality and durability the lumber or product made from it will have. The wood hardness coefficient is determined using the Brinnell method.

The method is as follows: a metal ball with a diameter of 10 mm is pressed into the surface of the sample with a force of 100 kg. Depending on the type of deformation and the diameter of the depression formed on the surface, the result is determined - the higher the coefficient obtained, the harder the wood. Each test sample is compared with the hardness of different minerals - from talc to diamond, indicating a hardness coefficient, which, accordingly, varies from 1 to 10.

Sucupira

The hardness of this rock is 5.6. Sucupira grows in South America. Mainly in Colombia, Brazil and Venezuela. Mature wood has beautiful reddish-brown tones. They also have inclusions of yellowish or light narrow veins, as well as a recognizable characteristic texture. Sukupira is quite decorative and at the same time practical. The wood is very durable and contains oily substances. The tree is not susceptible to pests and wood fungi. Only it is very difficult to process, but it is well polished and sanded.

Iron wood: description and application

To find an iron tree, you will have to try. The plant is listed in the Red Book. The characteristics of the culture indicate its high density, similar to cast iron. It's surprising that its bark cannot be pierced with weapons. However, it can completely drown in water.

Ironwood is not one type of tree, but many crops that belong to different types. Ironwood wood is characterized by high density.

The group of such trees includes many species that grow in different countries. Wood is actively used in manufacturing and healthcare.

Description of iron wood

It is difficult to determine whether a plant is an ironwood based on one species. Moreover, they are very rare. Therefore, a description of its main characteristics is of paramount importance. Their signs can be identified:

• life expectancy more than 200 years;
• wood is not subject to destruction and acid;
• a substance produced by the bark helps protect the tree from diseases,
• pests and fungi;
• low growth rate of the plant, in addition, it will drown if it is under water;
• the tree has a height of more than 25 m and a diameter of over 2 m.

All this helps the tree cope with severe frosts. A sudden change in temperature, dry weather or high humidity will not have an adverse effect on the condition of the crop.

She adapts remarkably well to the conditions of the external environment, whatever it may be. This is facilitated by the individual characteristics of the structure of the trunk and rhizome, as well as the content of useful substances in the bark.

This is the reason for the high popularity of such wood in industry. They are used for the manufacture of furniture, cosmetics, interior items, watercraft, in the field of construction, mechanical engineering, etc.

Proper processing of ironwood helps to remove beneficial substances that are effectively used in the fight against diseases:

• urinary system;
• dermatology;
• joints and muscles (rheumatism);
• gout.

Even the smallest bottle of oil from this tree is very expensive.

To obtain such an ether, it is necessary to process tens of kg of starting material. In this case, processing is carried out exclusively by hand.

Their branches were used to feed animals. Some peoples used wood for heating.

Birch Schmidt

This type of ironwood is also found in Russia. Representatives of this type can be found in Primorye. The oldest of them is more than 400 years old. The height can be almost 30 m. The girth of the trunk is approximately 85 centimeters.

Its main characteristics:

• The bark is gray-brown in color. She has a lot of damage. And a number of areas have detachments or peeling;
• Absolutely smooth branches. They are dark brown in color. From the outside you can immediately notice the resin on their bark. They also have a wonderful smell.
• Each leaf is characterized by an oval shape, the sides of which are sharp at the tip.

If you brew fresh leaves, they can be used to eliminate bile and, in addition, to treat wounds. Thanks to it, dermatological diseases can be cured. This unusual birch is found in northern Korea, Japan and China.

Prickly argan

More than 2 million such trees can be counted. They are mainly found in Morocco or Algeria. Unfortunately, there used to be much more trees of this species, and they even made up entire forests represented only by this species.

Merbau

Merbau is ready to boast a hardness of 4.9. Most of the red-brown wood comes from Intsia species. It is similar in texture, color and properties to the wood of trees of the Afzelia genus. The wood is hard and polishes well. The density is about 800 kg/m. In Europe, this wood is used primarily to create parquet. Due to its special hardness, merbau is suitable for the construction of public buildings. Due to the fact that it is resistant to moisture, it is used in the design of bathrooms.

Iron wood - types, photos and descriptions, wood features, video

article: Sequoia

What's special about these trees?

It is quite difficult to recognize the “stone” species of a perennial plant with the naked eye. Especially if they are on the verge of extinction. However, they are characterized by the following features:

• the age of such centenarians is at least 2 hundred years;
• wood fiber is resistant to corrosion processes and does not deteriorate under the influence of strong acids;
• the bark contains many tannins that protect their “hosts” from all kinds of parasites, as well as from rot fungus;
• the log will definitely go under water, since the density of wood is 1 t/m³, taking into account a humidity of 12%, for this reason such species grow quite slowly;
• the height of each exceeds 25 meters, and the girth of the trunk reaches more than 200 cm.

• furniture;

• building structures;
• cars;
• cosmetics;
• decorative elements;

• underwater technology.

From the fruits, bark and leaves of these “stone” varieties, extracts are obtained that are successfully used to treat:

• gout;
• diseases of the genitourinary system;
• terrible skin rashes;
• rheumatism.

The branches of these plants were used in ancient times to feed livestock. At the same time, for many Moroccan tribes, such durable wood served as fuel. The logs burned slowly and retained heat for a long time.

Birch Schmidt

Russia can also boast of such a landmark. In the coastal regions of this country, several dozen specimens of this “iron” birch are found. The oldest of them is about 400 years old. Each such tree grows up to 30 meters in height. Meanwhile, the trunk diameter of this “beauty” is 80-90 cm. The distinctive features of the Schmidt birch are:

1. Brownish-gray bark with a creamy tint. The surface of its mighty trunk is abundantly covered with deep cracks. In some places, peeling layers of bark or areas that are beginning to peel off are visible.
2. Perfectly smooth branches. They can be either black or brown, or the shade of overripe cherries. Outside observers immediately notice the resinous streaks on them. These “lentils” emit a pleasant aroma.

3. The shape of the leaves resembles an oval, with one side having a pointed end.

An infusion/decoction of freshly picked leaves or buds can be used as a choleretic agent and also for healing wounds. With its help you can overcome ringworm, eczema or acne.

Prickly argan

In the territory of modern Algeria and Morocco, according to the latest data, over 2 million copies of such a perennial plant grow. This is all that remains of the mighty forests, consisting of only argan.

In her homeland, she is a symbol and also a source of life for nomadic African tribes. Various household items were made from its wood. The fruits and leaves were eaten by both animals and humans.

The wood material lasted for a long time, because the height of the trunk was 10 m and above, and the circumference was more than 15 m.

Argan has a very powerful root system, capable of penetrating 30 meters deep into the soil. This protects the plant from dehydration and hurricane winds. Many inhabitants of Africa feed on its branches and leaves. But picking them is not so easy, because they are covered with sharp thorns.

West Africa (Republic of the Congo) also has its own representative of the stone/iron tree group. People call it "Shea", but in the world of botanists it is known as "Vitellaria amazing". But in the tropical latitudes of this continent the majestic “Winged Lofira” grows.

Temir-agach or Persian parrotia

In terms of strength, this particular deciduous tree has no equal. Its wood is several times harder than iron itself. In addition to Africa, parrotia can also be found in the Middle East.

The forests of Iran and Azerbaijan abound with these amazing specimens. Such trees look especially delightful in the spring when they bloom. Although they prefer warmer climates, they can still survive at -25°C.

The trunk of temir-agach is used for the production of:

• parquet/floor boards;
• frame;
• automotive components;
• ax handle;
• artistic elements.

Since such plants do not have elasticity and flexibility, they are used to make powerful “living” fences. Having grown and become stronger, they form an impenetrable thicket that protects the garden plot from uninvited guests.

Other representatives of the group

In addition to such popular species belonging to the “iron tree” group, there are many other “stone” plants. They grow on different continents and amaze with their strength, as well as unique healing properties. These include the following breeds:

1. Yew. Wood can retain moisture, but it does not rot.
2. A Christmas tree found in New Zealand. There are entire groves of such trees in this area. They only throw out the blossoms at Christmas.
3. Hop Grab. The climate of the subtropical zone suits it, so hop hornbeam grows just above the equator. Sadly, only fossilized remains of its wood have been found in Russia.
4. Mezuya. Asian peoples use the poisonous resin of this plant as a medicinal drug.
5. Brazilwood. The endangered species grows in the Amazon jungle in Brazil.
6. Guaiacum. It grows on islands located in the Caribbean. The resinous substances of this tree are used as stimulants.

As you can see, there are exceptions to the rules not only in linguistics, but also in nature. Such “iron” trees are an example of this. They have unusually strong wood that is unable to float on water.

Yarra

This wood grows in Australia. It is also considered a type of eucalyptus with a hardness of 4.7. The texture and color of yarra resembles mahogany. So it is often called Australian mahogany. Only the yarra is particularly brightly colored. It can be characterized by all shades of red. In advantage you can see from light pink to dark red. Wood darkens in light. It is decorative, hard and dense. It also polishes and sands well.

Features of hardwood

Typically, the quality of such rocks is assessed by three indicators - density, Brinnell hardness and cross-cut rigidity. On average, the density of such wood is about 1200-1400 kg/m3. As for the Brinnell hardness, this value can reach 3.5 kgf/mm2, and the cross-cut rigidity can be 80 MPa. Again, these indicators are typical for trees familiar to Russian conditions, and exotic species can have significantly superior characteristics. What types of wood are classified as hardwood in the temperate zone? Usually oak, beech, ash and some types of hornbeam are distinguished. It is important to consider that along with the positive quality of hardness, such trees also have negative properties. It has already been said that in order to improve its performance qualities, lumber can be subjected to additional processing. Sometimes hard wood is subjected to similar operations to obtain special physical characteristics. And here a serious problem arises, since many rocks, due to their high density, do not tolerate the processes of grinding, impregnation, and especially drying. Cracks, chips and other manifestations of structural deformation often form.

Pink tree

The Brinell hardness of rosewood is 4.4. Grows exclusively in Brazil. Rosewood wood is characterized by its color - from yellow to pink with a red pattern. There is also a rose scent. The wood is very dense and hard and polishes well. Rosewood is often used to make furniture for small other objects. For example, for humidors or for creating musical instruments.

Varieties of "iron trees"

As mentioned earlier, there are many trees with high hardness ratings that are classified as “iron trees”. Among the most widely used in production, construction, and for making furniture, the following can be mentioned.

Jatoba - Brazilian cherry

In the tropical forests of Central and South America grows a tree called the South American (Brazilian) cherry. The height of individual specimens can exceed 40 m. Young shoots, pubescent with small brownish hairs, form a wide crown. The compound leaves are composed of two pointed, crescent-shaped leaves measuring 7.5 cm in length.

The South American plant is not a relative of the cherry fruit tree, which is widespread in our country. Perhaps the plant received this name because of the wood, the core of which is dark red or deep orange. After cutting, within a week it very quickly acquires a dark, brick-red hue.

Jatoba is one of the hardest species (7 Brinell points) used for making furniture and decorative elements.

Sucupira

This is another representative of the South American flora, growing in the forest thickets of Colombia, Brazil, and Venezuela. Expressive texture, small, narrow yellowish or light veins on dull reddish-brown wood, lighter towards the edges, make it easily recognizable and very decorative. In addition to high hardness and strength, the distinctive quality of sucupira is the presence in the layers of wood of oily substances that prevent the development of diseases, damage by combs and other pests.

Hardness of about 5.6 points complicates the process of cutting wood, which requires strict adherence to technology, failure to comply with which can lead to damage to all harvested raw materials. But the processing (sanding, polishing) is quite simple, which makes it possible to obtain from it a high-quality, beautiful parquet flooring in a wide range of colors from cocoa with milk to a burgundy shade. Products made from sucupira do not fade under the influence of ultraviolet rays and are not affected by fungus or harmful insects.

About 100 years pass from planting until the plant reaches maturity, but once the tree reaches 25 years of age, it can be processed. At this time, its trunk is almost cylindrical, devoid of side branches and shoots.

Turmoil

In the West African tropical rainforests, a very interesting tree grows, reaching 50-60 m in height, with a trunk diameter of about 1 m. The color of its wood resembles the color of a walnut, and the structure is teak. This type of wood is called mutania. It belongs to the “iron” category, since its hardness value is 5 points. However, this value is not always sufficient and in some cases it can be damaged by mechanical stress.

Muthenia wood is valued by furniture makers and builders because it does not crack or warp during the drying process, and when cut, radial rays of a violet hue “appear” on it. High hygroscopicity does not allow wood to be treated with varnish or primer. But you don’t need to do this, because it has an original natural shine. Furniture is made from muthenia wood, it is used for interior decoration, and is used in the production of parquet and veneer.

Intsia

Under the name merbau, wood of various types of intsia is widely used in European countries for the manufacture of parquet. Possessing high hardness (4.9 Brinell points), it is even suitable for laying floors in public buildings. In addition, it has increased moisture resistance, which makes it possible to use it in bathrooms, baths, and saunas.

The distribution area of ​​Intsia is South Asia, Oceania, New Guinea, Madagascar. The plant belongs to the legume family. The height of individual specimens reaches 30-50 meters, the trunk diameter is 1.5 m. At the same time, there are practically no lateral branches on the trunk.

Merbau wood has a range of colors from light orange to yellow. After sawing, processing, and polishing, the surface of the wood becomes brownish and acquires a beautiful silver or bronze tint.

Canadian maple

The national flag of Canada is decorated with a stylized image of a maple leaf, since the sugar maple (Canadian) is a symbol of this country. Acer saccharum is a deciduous tree belonging to the Sapindaceae family. It occupies vast areas in North America. Maple also grows in our country, and recently it has been actively used in Europe as an ornamental plant to decorate gardens, parks, and public gardens.

The lifespan of one plant can be 400 years. During this time, it grows to 30-40 m in height, the thickness of the trunk reaches 1 m. The decorative appearance of the maple tree is given by its picturesque crown, consisting of small, about 11 cm in length and width, leaves of an original shape. In summer they are dark green, with the onset of autumn they acquire red, orange, and yellow shades.

In addition to its decorative properties, Acer saccharum has a sweetish-tasting sap, which can be collected in early spring and used in cooking, and durable, hard (4.8 Brinell points) wood, widely used for making furniture, expensive musical instruments, parquet, cladding panels, butts. for weapons and even bowling pins.

Yarra (eucalyptus)

In total, about 700 species of eucalyptus, trees from the myrtle family (Myrtaceae), grow in Australia. They grow very rapidly, especially at a young age, adding up to 5 m in height per year. The height of an adult plant is about 40-50 m. Among the features of eucalyptus: the ability to “shed” the bark in the fall, the arrangement of the leaves with their edges facing the sun, so they do not provide shade at all, the beautiful dark red to light pink color of the wood, the texture reminiscent of mahogany (mahogany) and high hardness (5 Brinell points).

Yarra – Eucalyptus marginata wood, dense, hard and flexible, can be easily processed: polished, sanded. But it has a drawback - it is very difficult to cut it perfectly straight. The main use of jarrah wood is decoration and cladding of yachts, boats, and buildings in areas with high humidity.

Pink tree

A very unusual tree, Dalbergia decipularis or bahia, grows in the Amazon jungle. It grows only in the subtropics of Brazil and is notable for its hard wood (4.4 Brinell points) with a beautiful texture, coloring from yellow to pink, with small red touches. But what is especially surprising is its smell. Bahia gives off an aroma characteristic of rose bushes. Because of this, the plant received another name - rosewood.

The wood is highly polished and used in furniture production, for the manufacture of musical instruments (recorders, guitars), gift boxes for cigars (humidors), and for wood carving. But still, its main value is its essential oil, which has antiseptic and bactericidal properties. It is widely used in cosmetology, dermatology, and is used as an analgesic and sedative. In addition, it is a powerful aphrodesiac.

Ash

Ash, which can be found in almost all corners of our country, has elastic, durable and hard (4.0 Brinell points) wood. It belongs to the Maslinaceae genus and, with an average height of 25-35 m, can sometimes reach a height of 60 m. The diameter of the trunk usually does not exceed 1 m. The special hardness of ash wood was noticed by the ancient Novgorodians. They used it to make combat (bows, clubs) and hunting (horns, spears) weapons.

Oak

In our country, oak is a kind of standard of hardness. We say: “Strong as an oak” when we want to emphasize the character traits of a person who has a strong will and determination. However, when compared with other “iron” trees, its hardness is not that great, only 3.8 Brinell points. Oak, a member of the Beech family, can grow both as a tree and as a shrub. Depending on the growing conditions, its wood varies in strength, strength, and heaviness. It is used as an ornamental wood, for the production of furniture, musical instruments, and as timber.

Ash

A genus of woody plants from the Olive family has a hardness of 4.0. The height of the tree is 25-35 meters. The trunk diameter reaches up to 1 meter. Due to its strength and elasticity, ash wood was used to create military weapons, as well as weapons for hunting. People made war clubs and spears from ash. They turned out strong, heavy and elastic. The ancient Novgorodians created bows from five ash plates glued together with bone glue.

Oak

The hardness of oak is 3.8. The genus unites about 600 species. Temperate regions of the Northern Hemisphere are considered the oak's natural habitat. Ornamental forest and oak trees are produced mainly by the named Russian-European species. Wood is distinguished by its strength, strength, hardness, density and heaviness. Quite often we see oak furniture. It is also used in the creation of musical instruments.

Coniferous wood

Today, in industrial and residential construction, frames are often needed, which are divided into two types - permanent and temporary. In addition, it is necessary to create floors, rafters, scaffolding and scaffolding. For these types of structures, lumber from coniferous trees is often used, which is explained by several reasons:

• Coniferous trees grow both in the Russian Federation and throughout the world. • Coniferous trees grow in a relatively short time, so the rate of timber harvesting is also accelerated. • Low-cost lumber from coniferous trees. • The bending strength of such trees reaches 74-79 MPa.

Pine and spruce are resistant to rotting processes and the negative effects of insects. However, there are differences between these types of trees.

Spruce

Spruce has a light white color. Every 20-30 cm there are small knots on its surface. The resin content of the lumber is minimal, the texture of the wood fibers is fine. There are “pockets” in the fibers where resin accumulates, flowing out during heating of the lumber.

There are small holes in the wood structure, since spruce is a favorite “food” for bark beetles.

Pine

This tree has a yellow-brown color and large fibers. Every 60-100 cm there are knots on the surface of the pine tree.

The weight of pine is greater than that of spruce, since its saturation with resin is higher.

Larch

The maximum bending strength of larch is 97 MPa.

In addition, if larch wood is in water, it becomes stone. In appearance it cannot be distinguished from spruce, but the latter weighs half as much.

Beech

Beech has the same hardness as oak. The height of the tree reaches 30 meters, and the thickness of the trunk is up to two meters. The trunk is smooth and covered with a thin layer of gray bark. As for beech wood, it is often used to create a variety of products: parquet, plywood, weaving shuttles, guitars, wooden containers, measuring instruments, and so on.