What is the strongest metal on earth? It may sound fairly straight forward; however, the answer to this question is quite complicated because comparing metals by strength does not work the way you think it does, why?
For starters, there is not a single standard for strength. At best there is four. Continue reading to learn about the four different types of strength and how they relate to metallurgy, and from there, you will have a better understanding of which metals are leading the pack in strength.
Determining the Strongest Metals: Types of Strength.
Tensile Strength
Tensile strength is a measure of a material’s resistance to tension, A tensile strength is using the amount of force it takes to stretch or pull something apart.
Something with low tensile strength will pull apart quicker then something with high tensile strength.
Compressive strength
Compressive strength is a measure of a material’s resistance to compression (being squeezed together). To determine compressive strength, external force apply pressure on a material, and register how far that material can compress.
A widely accepted test for compressive strength is Mohs Hardness Test, where a scale 1-10 is established for minerals from softest to hardest.
Yield Strength
Yield strength refers to a material’s resistance to permanent deformation or bending. This is an evaluation of the elastic limit of a material.
Typically determined through a bend test where the two ends of a beam (or bar) are held and stress is introduced; the goal is to determine how much stress it takes to exceed the material’s yield point or the point the material will not be able to return to its original shape when the stress is removed.
Impact Strength
Impact strength is the ability of a material to absorb a blow without fracture or shatter. In other words, this is a method of determining how much energy a material can accept as an impact.
Comparing Strong Metals
Due to the fact that strength is determined by a multitude of factors, there isn’t really an easy answer to the question, “What is the strongest metal on earth?” In fact, there are many metals, or substances, that are considered to be amongst the strongest.
Here we provide a list of some of the worlds strongest metals; this list places them in alphabetical order (and therefore should not be considered a ranking).
Chromium Strength
Chromium is a hard and brittle transition metal with a steel-gray coloration. Chromium is rated an 8.5 on the Moh’s Hardness Test, and therefore one of the hardest metals known. The only metals that rate higher than chromium on this test are boron (9.5) and diamond (10).
Inconel Strength
Inconel is a group of nickel based superalloys that are known for their properties at extreme temperatures. The tensile strength of Inconel can be between 103-160 ksi (vs. stainless steel’s score of 73.2 ksi).
This alloy is widely regarded as one of the strongest materials on earth due to the temperature resistant qualities of the metal.
Stainless Steel Strength
Stainless steel is an iron alloy distinguished from iron and other metals by its resistance to rusting and corrosion.
Since stainless steel has so many variations, stainless steel can have different amounts of strength for each unique alloy. Grade 304, stainless steel has incredible tensile strength of up to 621 MPa or 90 KSI.
Titanium Strength
Titanium is an elemental earth metal with an extremely high melting point. It has a significantly high strength-to-weight ratio, making it an ideal metal for applications where weight must be minimized, while strength must be maximized.
Tool Steel Strength
Tool steel is a carbon alloy used in manufacturing tools. Tool steel is one of the strongest metals sold on the market due to its hardness, abrasion resistance, and resistance to retaining shape at high temperatures. The ultimate tensile strength of A2 steel is higher than 1860 MPa.
Tungsten Strength
Tungsten is one of the strongest natural metals (142,000 psi). Conversely, tungsten is brittle — it can be known to shatter. Tungsten has a 9 on the Mohs scale of hardness.
Using the distinct types of strength summarized above it becomes very easy to see that picking the single strongest metal is an almost impossible task. In this instance, we can summarize tungsten vs titanium metals.
Tungsten vs Titanium
As stated above, tungsten is by far the strongest of any natural metal (142,000 psi). Through an impact strength evaluation, however, tungsten is weak — it is a brittle metal that is known to shatter when hitting an object.
While titanium soars at a tensile strength of 63,000 psi. Referring to titanium’s density again, if you are comparing both metals by a pound-for-pound basis, titanium displaces tungsten.
Far as compressive strength is concerned, titanium scores lower on the Mohs scale of hardness.
It is easy to see that an attempt to directly compare the two metals is a bit like comparing apples and oranges. whether that be chromium vs Inconel, titanium vs steel, or tungsten vs stainless steel — it just doesn’t work!