Hardwood is used for building furniture, but also for house construction and interior finishing. It is characterized by durability and a high density. The classification into hardwood and softwood depends on the density of the kiln-dried wood. Hardwood has a high weight. Most of the hardwood varieties are hardwoods. In addition to domestic varieties, there are also tropical hardwoods, which often have an even higher hardness. With tropical woods, however, you should consider the unfavourable ecological balance and look for domestic alternatives if possible.
What is hardwood?
The name hardwood already suggests that it is a solid, heavy wood. This wood has a high density and is therefore difficult to work with. However, it also has positive properties, as it is robust and durable. If you saw hardwood, you will soon realize that it is not so easy. Soft wood is easier to cut. The different types of hardwood differ in hardness.
What is hardwood? In order to give an exact definition, the density of the kiln must be used. Hardwood is wood with a kiln density of at least 0.55 grams per cubic centimetre or at least 550 kilograms per cubic metre. The kiln density differs between the different types of hardwood. Anything with a lower kiln density is softwood. The wood has a high density due to its high fibre content and its tight vascular structure. These woods grow only slowly. You can recognize this by the fact that in a cross-section through such a tree, the annual rings are close together.
What is the dry density?
Dry density is the weight of wood when it is completely dry, i.e. when it no longer contains any water. However, there is no such thing as absolutely dry wood, because wood absorbs moisture from its environment. The kiln density is therefore only a theoretical value that allows a classification into hardwood and softwood. The data for kiln density is always only an average value. The kiln density also depends on environmental factors during tree growth. The less sunlight, heat and nutrients a tree receives, the slower it grows. The season in which a tree is felled also has an influence on the kiln density. The location therefore has an influence on the kiln density. It can be concluded from this that the less favourable the growing conditions are, the harder the wood is. Wood from the far north, where the growing seasons are short, therefore has a higher hardness. An exception, however, is ironwood, which is extremely hard and comes from the tropics.
What are typical hardwood types?
What is hardwood? As a rule of thumb, when classifying hardwood and softwood, hardwood comes from deciduous trees and softwood from conifers. However, there are some exceptions. Poplars, lime trees and willows belong to the deciduous trees, but they do not provide hardwood, but softwood.
Based on the kilogram density per cubic metre, the following trees are typical suppliers of hardwood:
- Maple: 600 kg / m³
- Elm: 600 kg / m³
- Walnut: 610 kg / m³
- Hazelnut: 610 kg / m³
- Birch: 630 kg / m³
- Ash: 640 kg / m³
- Chestnut: 650 kg / m³
- Oak: 660 kg / m³
- Pear: 680 kg / m³
- Copper beach: 680 kg / m³
- Black locust: 690 kg / m³
- Hornbeam: 720 kg / m³
- Apple: 730 kg / m³
- Plum: 750 kg / m³
- Rosewood: 820 kg / m³
When selecting the different types of hardwood, for example for the construction of furniture or interior fittings, it is not only the density of the kiln that matters. An important decision criterion is the appearance, which is determined by colour, texture and grain. Elasticity also plays a role. There are various hardwoods that have a high kiln density but are elastic, for example oak, ash or robinia.
Ironwood - hardwood with extremely high dry density
Ironwoods are hardwoods with a density of more than 1 gram per cubic centimetre. Most of these are tropical woods. Unlike other woods, ironwood sinks in water due to its high weight. The reason for this is the density of water, which is about 1 gram per cubic centimetre. If the wood has a higher density, it will not float. Typical ironwoods are:
- Cumaru (Tonka tree), kiln density 1,100 kilograms per cubic metre
- Bongossi (Azobe), kiln density 1,200 kilograms per cubic metre
- Ebony, kiln density 1,200 kilograms per cubic metre
- Guaiac (pock wood), kiln density 1,400 kilograms per cubic metre
Due to their extremely high density, ironwoods are considered extraordinarily robust and weather-resistant. They are therefore ideal for outdoor use. Guaiac is the hardest wood in the world. Teak, by the way, is also a hardwood, but not ironwood. It has a density of only 630 kilograms per cubic metre.
Features of hardwood
Hardwood has a large number of fibres and is therefore strong. Due to its slow growth, this wood has a dense structure. It is often characterised by a beautiful grain. Although the dense structure has no influence on weather resistance, it makes the wood more resistant to shocks, impacts and other mechanical effects. Hardwood takes a relatively long time to dry. To work the wood, you usually need special equipment and sufficient craftsmanship.
The different types of hardwood have different properties. Robinia wood is considered valuable because it is robust and extremely resistant to weathering and rotting. It is hard, but still flexible. Chestnut wood is considered noble because it has a fine texture. Beech wood has similar properties to chestnut wood. Maple is robust and weather-resistant. Oak is hard, yet elastic and permanently weather-resistant.
Differences between hard and softwood
Hardwood and softwood differ in their kiln density. All woods with a kiln density of less than 0.55 grams per cubic centimetre are softwoods. Most softwood comes from conifers. Softwood has fewer fibres. Because these trees grow faster, the annual rings are further apart than in hardwoods. Softwood is easier to work with. One disadvantage of softwood compared to hardwood is its lower load-bearing capacity. Although softwood can also be used for interior finishing, it is used where it is only subject to minor stress. It is easy to shape and is therefore mainly used for decorative purposes.
Diverse uses of hardwoods
What is hardwood? This wood is characterized by a high degree of resistance and resilience. It is therefore used wherever a strong stress occurs, for example Construction of furnitureBut also for floor coverings, stairs, ship floors, ship's decks and garden furniture. Different hardwood types are also used to build Windows and doors, musical instruments and used as industrial trees. You can also make different decorations from the wood, for example sculptures or pictures. Not to be forgotten is the use as firewood, as it has a good calorific value and burning slowly and evenly due to the high density.
What you should consider in tropical woods
Tropical woods are characterized by excellent properties and sometimes also offer a beautiful appearance. However, you should not forget that this wood has travelled a long way and thus has a strong impact on the environment. These types of hardwood often grow in rainforests. During the extraction of these woods, large parts of the rainforest are often cut down or completely destroyed. Habitat for many plant and animal species is lost. The rainforest is also the green lung of the earth, as it binds large amounts of carbon dioxide. Sometimes tropical timber comes from illegal logging. If you want to be environmentally conscious, you should choose European wood as an alternative. You are on the safe side if you buy hardwood with the FSC seal, which comes from sustainable forestry. Of course, you can also have furniture made of tropical woods restored.
Edit hardwood with the Mr Beam Laser cutter
Do you want to decorate hardwood with beautiful engravings, help you Mr Beam Laser cutter included. The result is all the better, the more even the colouration and grain of the wood. For example, with the laser cutter you can give furniture a very personal engraving according to your taste. You can also do your very own works of art like pictures Or make small sculptures. Thin wood you can also cut with the laser cut. Of the Laser Cutter also allows filigree shapes and patterns. - very easily Wood laser with the Mr Beam.
You have the article from our Materialguide to like? We have more interesting articles on different materials like felt, leather, plywood or slate. In addition, we also publish regularly Tutorials in our Mr Beam Blog.
