What Are the Strongest and Hardest Metals Known to Man?
Which Metal Has the Most Tensile Strength or Hardness?
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.
But what is the strongest metal, and just how strong is it?
The answer to this question depends on how the question itself is framed. Does the practicality of using a 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.
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 honor 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 with in 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).
An alloy is a metal made by combining two or more metallic elements. This is usually done to achieve greater strength and/or resistance to corrosion.
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 honor 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 armor 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.
These metals are the backbone of modern industry, providing the support that keeps our daily lives running smoothly. Whether in the tip of a pen, on the fuselage of an airplane, or in the beams of a tall building, we rely on metals to protect us as we seek to progress ever further. We should consider ourselves lucky that, no matter what our needs, there is something in nature to cover them.