What is the world’s strongest metal? This is one of those questions that sounds simple enough but is actually 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.
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.
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 Mohs Hardness Test. The test relies on a scale which rates minerals from 1-10, or softest-hardest.
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. 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.
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, there are several metals that 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.
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 really 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.