According to economists, the global materials testing market is worth $569.2 million. And, it’s only projected to increase in value.
This hot, growing sector is all about evaluating materials—from silk to steel. Want to explore the field? Start with the basics first: learn about tensile strength.
What is Tensile Strength?
Tensile strength quantifies the endurance and resistance of a material under tension. In essence, a materials’ tensile strength tells you the degree of force it takes to pull a material apart. The International System measures tensile strength in pascal units (Pa).
When a material has a high degree of tensile strength, it can resist pulling forces. It can also hold together under stress while it’s pulled taut.
Engineers can plot out a material’s relative tensile strength on a stress-strain curve. The stress-strain curve shows how the material behaves under a load.
The yield point is the point where the material stops performing like an elastic, and it starts performing like a plastic. A brittle material’s yield point is the same as its tensile strength (or near to it). A ductile (highly malleable) material’s tensile strength is higher than its yield point.
Tensile strength is more critical for brittle materials.
Why Tensile Strength Matters
Tensile strength matters because it sets limits on what a given material can be used for safely. An object’s TS tells developers how much weight a material can carry, and in what temperatures and conditions. A material’s tensile strength is subject to the effects of temperature and moisture.
Tensile strength tests can also demonstrate how a material begins to fail under excessive stress. A material that warps has different possible uses than one that just snaps.
The tensile strength of a rubber band tells you how intensely it can stretch before it breaks. The tensile strength of a crane cable gives you a hard limit to how heavy a load the crane can lift.
What is the Tensile Strength of Steel?
Steel’s tensile strength varies. Steel is an alloy of iron and carbon. The ratio and structure of those elements differ from one type of steel to the next. This, in turn, alters the steel’s properties—including its tensile strength,
SAE grades steel alloys according to the percentage of carbon in the material. You can access the SAE’s standards for tensile strength per grade of steel through its databases. Manufacturers typically publish the tensile strength of steel products they offer by grade.
How to Perform a Tensile Strength Test
To test a material’s tensile strength, you must clamp a sample of the material between two grips. The material should stretch vertically, with one grip above it and the other below it.
The grip above the material must be secured. It does not move during the test.
Then, add weight to the grip beneath the material. As you add weight, the lower grip exerts more force on the material. Eventually, the material will reach its yield point and begin to deform.
This is the point of maximum withstandable stress. Continue the test, and eventually, you will discover the material’s fracture point.
Gravitational force is not the only force scientists use to determine a material’s tensile strength. In 2019, Quality Magazine, a materials science trade publication, published an overview of the most popular tensile strength tests.
The article covers the benefits and drawbacks of each approach. Which one appeals to you?
Get in the Know, Now
Learning about tensile strength is a great first step into the materials testing marketplace. But, there’s a lot more to learn! Discover more tips, strategies, and the latest innovations when you browse the rest of our content library.