If you are trying to determine what kind of wood to use for your next big woodworking project, one good option to consider is aspen. This is a very popular type of wood, especially in North America.
With that being said, you might be wondering whether it is a hardwood or a softwood, and you’re probably wondering just how strong it is. Well, today we are here to figure out exactly that. So, how strong is aspen?
Is Aspen a Hardwood or Softwood?
The aspen tree is a deciduous angiosperm. This means that it is a flowering tree that loses its leaves during the colder seasons. As is the case with aspen, this also generally means that it is a hardwood. With that being said, this is one of the softer hardwoods that we have in North America, and in the whole world. There are a few different types of aspen, but they are all extremely soft.
Aspen Wood Strength: All You Need to Know
In the grand scheme of things, no, aspen is not the strongest type of wood around, which is funny seeing as it is technically classified as a hardwood. Now, we want to use five different factors to see just how strong this wood is.
These factors include compressive strength, bending strength, stiffness, hardness, and density. Furthermore, there are also three different kinds of aspen trees that we will be taking a look at, the bigtooth aspen, the quaking aspen, and the European aspen.
Compressive Strength
Let’s now take a look at the compressive strength of all three varieties:
- European Aspen – 5,080 lbf per square inch (35.0 MPa)
- Quaking Aspen – 4,250 lbf per square inch (29.3 MPa)
- Bigtooth Aspen – 5,300 lbf per square inch (36.6 MPa)
Out of all of the different types, bigtooth aspen is the one with the highest compressive strength. When compared to other types of wood, especially hardwoods, aspen is low down on the list in terms of compressive strength.
When compared to other types of hardwood, aspen has one of the lowest compressive strengths around. There are even some types of softwood, such as black spruce and Douglas fir for example, that have higher compressive strengths.
The compressive strength of wood is also known as the crushing strength. This refers to how much weight a piece of wood can take a parallel to its grain. For a visual example, picture a table leg holding up a table. How much weight could you put on that table before the table leg gives out and snaps?
Bending Strength
Let’s now take a look at the bending strength for all three types of aspen:
- European Aspen – 8,990 lbf per square inch (62.0 MPa)
- Quaking Aspen – 8,400 lbf per square inch (57.9 MPa)
- Bigtooth Aspen – 9,100 lbf per square inch (62.8 MPa)
Bigtooth aspen does have the highest bending strength of all aspen types, although this is still fairly low. In terms of hardwoods, it’s very low down on the list, and there aren’t many types of wood that have a lower bending strength.
Virtually all types of hardwood have a higher bending strength, as well as some types of softwood, such as Douglas fir.
For those of you who don’t know, the bending strength of wood may also be referred to as the modulus of rupture. This measurement refers to how much weight a piece of wood can handle perpendicular to its grain, unlike compressive strength, which measures parallel to the grain.
As an example, picture a stick that is mounted to a wall horizontally. How much weight could you hang on the end of the stick before it snaps and crashes downwards?
Stiffness
let’s now take a look at how stiff all three types of aspen are:
- European Aspen – 1,414,000 lbf per square inch (9.75 GPa)
- Quaking Aspen – 1,180,000 lbf per square inch (8.14 GPa)
- Bigtooth Aspen – 1,430,000 lbf per square inch (9.86 GPa)
The bigtooth aspen is the stiffest of all the varieties. However, when compared to other types of hardwood, it’s not very stiff at all. In fact, it isn’t even as stiff as some types of softwood. Both spruce and Douglas fir are much stiffer than aspen. In the grand scheme of things, this wood is just not very stiff at all.
In case you don’t know, the stiffness of wood is also known as the modulus of elasticity. This refers to how much weight a piece of wood can take in its center before it begins to sag or bend.
For an easy-to-visualize example, picture yourself standing on a board that is being supported on either side by bricks. How heavy would you have to be to force the board to bend or sag in the middle?
Hardness
Let’s now take a look at how hard all three types of aspen are:
- European Aspen – 380 lbf
- Quaking Aspen – 350 lbf
- Bigtooth Aspen – 420 lbf
The hardest type of aspen is the bigtooth aspen. When compared to other types of hardwood, aspen is actually very soft, and there really aren’t any types of hardwood that are any softer. As is the trend, there are also some softwoods that are much harder, such as sugar pine and Douglas fir.
The hardness of wood simply refers to how hard that outer surface is. In other words, how resilient is that piece of wood towards physical damage such as denting or scratching? This is usually measured on the Janka hardness scale.
Density
Let’s now take a look at how dense all three types of Aspen are:
- European Aspen – 28 lbs per cubic foot (450 kg per cubic meter)
- Quaking Aspen – 26 lbs per cubic foot (415 kg per cubic meter)
- Bigtooth Aspen – 27 lbs per cubic foot (435 kg per cubic meter)
The European aspen is actually the densest of all aspen types. In terms of other hardwoods, aspen is not very heavy at all, with the vast majority of other hardwoods in the world being much heavier and denser.
Black spruce, which is a softwood is also 28 lbs per cubic foot, while Douglas fir is even heavier.
The density of wood refers to how heavy a piece of wood is in reference to a certain size. This is generally measured in either pounds per cubic foot or kilograms per cubic meter. This is important to know because it will help you determine just how strong a piece of wood is, and it also helps determine how difficult a piece of wood is to work with.
Is Aspen Wood Strong?
It’s not like aspen is a bad type of wood at all, but in terms of hardwood, it’s really not very strong at all. It’s classified as a hardwood due to being a deciduous angiosperm, but it’s actually not very hard or dense at all. It also doesn’t have a very high bending strength, compressive strength, or modulus of elasticity.
In the grand scheme of things, we would say that aspen wood is not very strong. It’s still fine for basic indoor and utilitarian purposes, but just don’t expect it to be overly structurally sound or to bear a lot of weight.
Summary
What it all comes down to here is that aspen, technically a hardwood, is actually no stronger than many types of softwood out there. This doesn’t necessarily mean that it is a bad type of wood, but you do need to know what it can and cannot be used for.