What are the strongest metals?
This is one of those questions that sounds simple enough but is quite complex. When it comes to metal, making direct comparisons based on strength doesn’t work. Why? First of all, because there isn’t a single, universal scale for strength. At best, there are four. In today’s blog, I’m going to outline these four types of strength as they relate to metallurgy before giving some insights and comparisons of the metals leading the pack in terms of strength. Let’s get started.
Today we are looking at the strongest metals in the world. For obvious reasons, scientists, designers, and engineers need to be aware of the properties of the many elemental metals and their myriad alloys.
A number of properties determine the strength of a metal or alloy, and when choosing a metal, the one chosen must have the correct properties for the application. For instance, for overall strength, nothing beats steel. If you want hardness, then Tungsten is the one to go for, and a close contender to both steel and Tungsten, with properties close to both is Titanium.
Of course, Diamond is harder, and Graphene is tougher, but we are limiting our list to the ten strongest metals in the world.
Although there are several different definitions of strength, including hardness, yield strength, and compressive strength, this article focuses mainly on tensile strength, which is the force required to stretch an object or pull it apart.
The first three metals on the list are elements found in nature, while the last three are human-made mixtures of elements (alloys) crafted for applications requiring high strength. The strongest pure or natural metals can’t match the strength of alloys specifically designed for high strength, along with other useful properties such as heat resistance, durability, biocompatibility, and corrosion resistance.
Human technology progresses more and more every day. Modern industrial processes require materials capable of withstanding immense pressures while retaining their shape and integrity. For this, engineers generally turn to metals due to their wide availability and malleability.
The answer to this question depends on how the question itself is framed. Does the practicality of using metal in any significant amount count? Does it have to be a natural metal, or are alloys considered? What’s the difference between strength and hardness? This article attempts to examine the multiple answers to this question, covering each metal with a claim to the title, and arguing its case.
Note: For the sake of clarity, the ‘strength’ considered is tensile strength, which is how much force an object can withstand before warping unless otherwise stated.
Determining the Strongest Metals: Types of Strength
Tensile strength refers to a material’s ability to resist tension. In other words, it looks at the amount of strength required to stretch or pull something apart. A material with low tensile strength would pull apart more easily than a material with high tensile strength.
When we speak of tensile strength, we are looking at the measurement of the force which would be required to pull something such as a cable, wire, rope, or a structural beam such as a girder to the point at which it breaks. The measurement is the maximum amount of stress before breaking, usually measured in pounds per square inch (PSI).
As an example, cookie dough has low tensile strength, and steel has high tensile strength.
This is a measure of how well the material resists being squeezed. In more basic terms it is the hardness of the material. This can also be measured in Psi. Another way to measure compressive strength is the use of the Mohs scale. On this scale of 0-10, 0 is the softest, and ten is the hardest. Not surprisingly, diamonds are ten on the scale. Compressive strength is an important property of tooling materials.
Compressive strength refers to a material’s ability to withstand being squeezed together (compressed). To test compressive strength, an external force places pressure upon a material, tracking to what degree the material can resist size reduction. A widely accepted test for compressive strength is the Mohs Hardness Test. The test relies on a scale which rates minerals from 1-10, or softest-hardest.
Yield strength refers to how well a beam made from a particular metal resists being bending and permanent deformation. This is a very important measurement for structural engineers. Metal will bend to a certain degree, and this is the elastic state, a state when the metal will return to its original shape after being bent, a useful property of spring steels. Once the metal has reached the plastic state, it has failed. This is measured in MegaPascals (Mpa)
Yield strength refers to a material’s ability to withstand permanent deformation or bending. It’s a way of testing the elastic limit of a given material. It is usually determined via a bend test where two ends of a beam or bar are gripped, and stress is applied. The intent is to discover how much stress it requires to exceed the material’s yield point or the point at which the material will not return to its original shape upon removal of the stress.
The ability of a material to resist impact without shattering. Going back to the diamond, it has a Mohs scale of 10 but can be shattered when struck with a hammer. Whereas steel can be struck with a hammer without shattering, the hammerhead itself is steel.
Impact strength refers to a material’s ability to withstand a blow without fracturing or shattering. In other words, it’s a method for determining the limit of how much energy a material can absorb via impact.
Comparing Strong Metals
Since a metal’s strength depends on multiple factors, there isn’t a simple answer to the question, what is the strongest metal? Instead, several metals are known to be among the strongest. I’ve chosen to list them in alphabetical order. Please do not take the following list’s order as a ranking.
- Carbon Steel
- Stainless Steel
- Tool Steel
Using the different types of strength outlined above, it’s easy to see why choosing the single strongest metal is difficult. For instance, let’s look at Tungsten vs Titanium.
The Top 10 Hardest Metals on Earth
Tungsten is one of the hardest metals you will find in nature. Also known as Wolfram, the rare chemical element exhibits a high density (19.25 g/cm3) as well as a high melting point (3422 °C/ 6192 °F). In its rare form, Tungsten is hard to work with due to its brittleness which can be changed when turned pure. Tungsten is often utilized to create hard alloys, such as high-speed steel to increase protection against abrasion as well as improve electrical conductivity.
The meaning of the Tungsten itself is ‘heavy stone’. Further, it is a grey-white lustrous metal that has the lowest vapour pressure. Moreover, it has the highest melting point, so it gets used in the making of light bulbs.
Furthermore, it has the highest tensile strength at 1650°C. Apart from this, it has an atomic number 74 in the periodic table. The melting point at 3410°C and boiling point at 5530°C. As a result, the Tungsten is one of the hardest metal present on Earth.
Chromium holds the second position in the world’s strongest metal on Earth. It is a steel-grey and lustrous metal with atomic number 24. The use of Chromium is in making the stainless steel alloy. Furthermore, Chromium metal has corrosion resistance and hardness, so it has a high value. The Melting of Chromium is 1907°C, and its symbol is ‘Cr’.
Chromium is the hardest metal known to man. While you may not have heard of Chromium, more than likely you’ve heard of stainless steel. Chromium is the key ingredient in stainless steel. Thus it is used in a variety of settings.
Titanium is a lustrous metal with silver colour. It is said to be the ninth most abundant element in the Earth’s Crust. Moreover, it is low density and high in strength. Titanium has a very useful property which is its Strength-to-Density ratio.
Furthermore, it’s stronger than steel but is less dense. The melting and boiling points of titanium metals are 1668°C and 3287°C respectively. The use of Titanium is for making strong and lightweight alloys for aerospace.
Titanium is a silvered coloured metal with low density and high strength. It is notable for having the highest tensile strength-to-density ratio of any metallic element. However, it’s not as hard as some varieties of heat-treated steel.
Titanium is commonly alloyed with a range of elements including iron, aluminium, and vanadium. Titanium alloys are strong and lightweight, making them ideal for automotive, aerospace, military and industrial applications. Two-thirds of all titanium metal produced is used for aircraft parts. Titanium is also highly resistant to seawater corrosion, making it perfect for propeller shafts and rigging as well as divers’ knives.
Gadolinium has an atomic number 64. It is silvery earth metal after removing the oxidation. Moreover, it is a malleable and ductile rare-earth metal..Above all, Gadolinium has a tensile strength of 430 x 106 Pa. Moreover, the melting point if this metal is 1312 °C and the boiling point is 3250 °C.
Iron is one of the most abundant elements found on Earth. It has an atomic number 26. Furthermore, iron is the main component in making steel alloy. Iron is corrosive because of which steel is an important alloy of it. Iron is one of the hardest metals in the world. It has a melting point of 1538°C.
Vanadium comes after iron in hardness. Furthermore, it is not corrosive. The melting point of vanadium is 1910°C. Moreover, the use of vanadium is in making the steel hard for automobiles parts.
Lutetium is one of the rarest elements on Earth. Therefore it is one of the most expensive metals. Furthermore, the melting point is 1663°C. Lutetium has its use in the petroleum industry. Moreover, in the process of polymerization, alkylation is also used.
It is a greyish-gold metal that has an atomic number 40. Its major property is it is highly corrosive resistive metal. Furthermore, the melting point of Zirconium is 1855°C. Moreover, its uses are in nuclear reactor tubing. Moreover, in households, it uses in making scissors and knives.
Osmium is a metal that is used in making fountain tips. Further, the melting point o Osmium is 3033°C. Furthermore, it looks like vibrant bluish-white metal. The atomic number is 76, and it’s further used in the making of strong needles and electrical constants.
Tantalum is useful in making capacitors and high power resistors. The melting point is 3020°C. Furthermore, it is used in the surgical industry because it is inert to the human body.
The Strongest Natural Metal: Tungsten
As far as pure metals go, Tungsten has the highest tensile strength, with an ultimate strength of 1510 megapascals. Tungsten also has the honour of having the highest melting point of any unalloyed metal and the second highest melting point in the whole periodic table—only carbon can withstand hotter temperatures. Tungsten is very dense and brittle, making it difficult to work within all but its purest forms. Tungsten is commonly used in electrical and military applications, and you may find tungsten filaments in light bulbs and tungsten coating that adds a real punch to projectiles. It is also a common component in steel and other alloys, where even a small amount can significantly increase the strength of the alloy.
A megapascal (MPa) is a metric pressure unit, mostly used in hydraulic systems that gauge high-pressure ratings, that equals 1,000,000 newtons per square meter (which is a pascal). 1 MPa is equal to 10 Bar.
The Strongest Alloy: Steel
Alloys are a constantly changing field, as researchers attempt to create ever-stronger combinations of elements. Generally, the strongest alloy is steel mixed with a few other elements. Vanadium steel alloys seem to be particularly promising, with several companies releasing variants with ultimate strengths of up to 5205 MPa. The steel that holds this distinction is called Micro-Melt® 10 Tough Treated Tool Steel.
Steel itself is an alloy of iron and carbon, although other elements can also be used. Steel is a highly versatile alloy, meaning a form of it can be made to meet almost any specifications. Steel has been in use for millenniums but became a more exact science during the Renaissance (1300-1700).
The Hardest Metal: Chromium
The ‘hardness’ of a mineral is generally determined by the Mohs scale and is defined as the scratch resistance of a mineral. Diamonds are the hardest minerals known to man, but what is the hardest metal? That honour goes to Chromium, a metal perhaps best known as the key ingredient in stainless steel. Chromium is also commonly used in chrome plating, which acts as a form of protection against corrosion and physical damage.
Chromium has been recognized for its unique traits since the Qin Dynasty in China when weapons and armour were coated with the metal and survive to this day, uncorroded and in perfect shape.
The Most Useful Strong Metal: Titanium
With an ultimate strength of about 434 MPa, Titanium is the perfect blend of strength and practicality. Its low density makes it perfect for industrial uses requiring a strong metal with a high melting point. Indeed, Titanium has the highest strength-to-weight ratio of any natural metal known to man. Pure Titanium is stronger than standard steel, while being less than half the weight, and can be made into even stronger alloys. Because it is also fairly common, it’s no wonder that Titanium is used for a multitude of purposes. When it comes to manufacturing, the only strong natural metal worth caring about is Titanium.
Tungsten vs Titanium
In terms of tensile strength, Tungsten is the strongest out of any natural metal (142,000 psi). But in terms of impact strength, Tungsten is weak — it’s a brittle metal that’s known to shatter on impact. Titanium, on the other hand, has a tensile strength of 63,000 psi. But when you figure in Titanium’s density and make a pound-for-pound comparison, it beats Tungsten. Looking at Titanium in terms of compression strength, it scores much lower on the Mohs scale of hardness.
It’s easy to see that trying to make a direct comparison is a bit like comparing apples to oranges. Whether you look at Chromium vs Inconel, Titanium vs steel, or Tungsten vs stainless steel, it just doesn’t quite make sense.
Part of the difficulty is that knowing which material is the strongest depends on what’s going to be done with it. There may be an application where a high yield strength is vital, but the compressive strength is a non-factor. Understanding the application is essential to selecting the proper materials. That’s a large part of the reason why we focus on a consultative relationship with our customers at Mead Metals. The conversation isn’t only about what a customer wants but what they want and need it to do. Armed with the right information, we can recommend (and oftentimes provide) the material best suited to a particular project or application.
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