There are numerous types of wood in this world, each with its distinctive characteristics and thicknesses. But what is the hardest wood? Well, the significance of hardness of wood relates to the amount of actual wood density that one volume of wood contains. This is also referred to as wood density.
It is important to know how much wood density a particular tree has as it tells us about the tree’s yield, quality, large variation and genetics. Other contributory factors of wood density include the age of the tree, its diameter, silvicultural treatment, height, geographical location, site of growth, seed source and growing conditions.
Janka Hardness Test
Invented by Gabriel Janka, a wood researcher from Austria, this scale measures how far a particular kind of wood resists wear and tear, and denting. By figuring this out, one can determine whether a particular kind of wood is apt for flooring or any specific use one might want it for.
The hardness of a particular kind of wood varies depending on the direction of its wood grain. Wood’s hardness is measured in different dimensions across the world, for instance in the US, it is expressed in pounds-force (lbf), in Australia, it is either in newtons (N) or kilonewtons (kN) and in Sweden it is in kilograms-force (kgf).
How a Janka hardness test is conducted
This test is conducted by embedding a 0.444-inch metal ball to half the diameter of the ball into a specimen of the surface of a knot-free wood. Two parts on the surface of each specimen are subjected to this test and the resulting information is recorded and the average found. Translated, the Janka rating of a particular species of wood refers to the measurement of the amount of force required to send the steel ball into the wood.
A good Janka rating
Before choosing a flooring type for your home, it’s good to know the Janka scale ratings of your prospective woods. This will give you an idea of how much wear and tear these woods can withstand, and therefore their cost-effectiveness in the long run. Despite this, a good rating on this scale is a mere indicator since a wood’s hardness isn’t the sole factor that impacts one’s buying decision. The look of a particular kind of wood, its durability, maintenance and prevention are also strong factors that influence buyers.
A bad Janka rating
Almost at the end of the Janka rating scale is Balsa wood, ranking 100. This wood is generally used for making crafts, since it is a very soft wood. So, if you were looking for flooring material, Balsa would not be the one to go with, since it is soft. Flooring material needs to be hardwood to withstand the rigors of regular and rough use. Hence, any wood with a rating of 1000 and more would be considered for this. So, a bad rating simply means a particular wood’s inappropriateness of use for a specific reason.
Even with a Janka rating in hand, buyers will never go solely by that as this scale is a mere indicator of the wood’s toughness. When one buys flooring material, a lot depends on how eye-catching it is and its price, apart from its durability and maintenance. In terms of durability of the wood, buyers need to be sure that it will withstand pulling, scraping and protracted positioning of furniture in one spot; scratching the surface of the flooring by pets and children who play with sharp-edged toys on the floor.
Top 10 hardest woods in the world
If you’re in the market for the hardest wood, here are the top 10 to choose from:
- Australian Buloke: Also called Allocasuarina luehmannii, this is a species of the Australian
ironwood tree. It is reputed to be the hardest wood worldwide, and has a Janka hardness rating of 5,060 lbf (22,500 N).
- Schinopsis brasiliensis: The Schinopsis brasiliensis is a species of the cashew plant, with its origins in Brazil. It is a very tough wood with a Janka rating of 4,800 lbf. Since it is so very tough, it is successfully used for construction purposes.
- Schinopsis balansae: If you ever visit Argentina or Paraguay, you will see large stretches of forestland comprising this hardwood tree. It grows to a fantastic 24 metres in height and has an equally amazing hardness rating of 4,570 lbf.
- Lignum vitae: Indigenous to the Caribbean and the north South American coast, Lignum vitae is
a trade wood, originating from the Guaiacum species of trees. It has been known for its strength and density since the 16th century and continues to be used even today to make sports goods, policemen’s truncheons and to treat a range of medical conditions such as cough, arthritis and skin conditions. It has a Janka hardness rating of 4,500 lbf.
- Piptadenia Macrocarpa: The Piptadenia Macrocarpa variety of wood comes from trees that originate in Bolivia, Argentina and Peru. With a 3,840 lbf Janka hardness rating, this variety of wood is perfect for a range of construction needs.
- Snakewood: This exotice hardwood is reputed for its unique grain. It is chiefly grown in South America where it is used in projects requiring really tough wood. Its Janka rating is 3,800 lbf.
- Brazilian Olivewood: This wood is a superb combination of hardness, attractive looks, strength and a fantastic Janka rating of 3,700. It is widely used to make elite and exotic furniture for the home.
- Brazilian Ebony: Originally from Brazil, Argentina and Paraguay, this dense wood isn’t just hard, but durable, shock-resistant and extremely cost-effective and practical choice of hardwood. It is best used for planking and decking, what with a 3,692 lbf Janka rating.
- Brazilian Walnut: This wood, home to Central and Latin America, has a unique grain that could
be straight, irregular or even interlocked. It is very dense, as is depicted by its Janka rating of 3,684 lbf, and is therefore best used in outdoor woodworking projects.
- African Pearwood: Grown largely in Cameroon, Nigeria, Republic of Congo, Angola and Gabon, the African Pearwood is mostly found in the tropical lowland forests of these countries. It is extremely hard as its Janka rating of 3,680 lbf shows.