If you’ve read our blogs on metals and alloys—particularly as they relate to ENDURA steel—you’ve probably heard the team from Titus Steel talking about tensile strength and yield strength. For those who are new to the steel game, we’re going to take a deep dive to explain what they mean.
What’s the Difference?
The biggest difference is that tensile measures catastrophic failure, where yield just measures the start of permanent deformation.
Tensile strength is the resistance of steel up to its breaking point. Once a piece of steel is pulled past its tensile or breaking point, it will break.
Tensile strength will show how much stress the steel can withstand until it leads to failure in two ways:
- Ductile failure – Think of this as the preliminary stage of failure, where it is pushed beyond the yield point to permanent deformation. It may technically still be in one piece, but the metal is critically and permanently compromised.
- Brittle failure – This is the final stage where the tensile strength measurement is taken. A brittle failure is when a metal snaps or cracks, often with no evidence of ductile failure.
Silly Putty is a great way to demonstrate these two failures: If you pull the putty slowly, it will stretch out and sag in the middle like a ductile failure. If you tear it quickly, it will snap in the middle like a brittle failure.
In essence, tensile strength is measured by the maximum stress that the steel can withstand while being stretched or pulled before breaking.
Part of ENDURA steel’s strength and durability comes from its plasticity, or its ability to slightly change shape to absorb pressure. Yield strength is the maximum stress that can be applied before it begins to deform or change shape permanently. This is called the elastic limit of the steel, or the ‘yield point’.
If stress is added to the metal but does not reach the yield point, the steel will return to its original shape after the stress is removed. If the stresses exceed the yield point, however, the steel will not be able to bounce back to its original shape. Yield strength represents the upper limit of the load that can be safely applied to the metal without deforming it, which makes it a very important number to know when designing components.
ENDURA steel’s TRIP (Transformation Induced Plasticity) properties help to diffuse pressure and impacts throughout the material, producing a much higher yield strength than regular abrasion-resistant steels.
Elongation is the percentage that the steel can be stretched before it breaks. It shows how ductile the steel is. Ductility is the ability of the steel to be stretched out without becoming more brittle or weaker in the process. The more ductile it is, the more formable the product is, which means the more it can be deformed without experiencing tearing, or fracture.
The impressive elongation property of ENDURA steel makes it much easier to work with, allowing for greater bend angles and more aggressive forming operations without cracking.
All 3 measurements are important in choosing a grade of ENDURA steel.
If you’re interested in learning more about the most tensile, high-yield, ductile steels on the market, we invite you to read more on ENDURA steel and ENDURA Dual. If you want to learn more about steel working in general, we suggest our Mechanical Properties in Selecting Steel, Quenching and Tempering Steel, or What is Steel Made From articles. Or, if you have any questions at all, you can always feel free to reach out and give us a call.