Stack of Steel PipesTensile and impact strength are two important considerations when choosing a type of metal to use for structural applications. Understanding what these mechanical properties are and why they’re essential is the key to finding the correct metal for your project. It will also help communicate the job requirements better to your steel fabrication partner.

What is tensile strength?

This is the value that identifies a metal’s ability to resist failure and deformation when loads that pull it apart are applied. Tensile strength is quantified through Pascals (Pa) or units of pounds per square inch (PSI).

There are three different types of tensile strengths. The first one, tensile yield strength, indicates a metal’s durability before it begins to plastically deform. Next one is the ultimate tensile strength, which is the maximum tensile strength of a metal. It’s usually measured when plastic deformation starts. The third type, the fracture tensile strength, is the degree to which the metal reaches the final point of failure.

Be sure to check for the documented tensile strength, especially if you’re working on towing or lifting, fasteners, and structural metals for building construction.

What is impact strength?

This measures the metal’s ability to absorb collision energy while resisting fracturing or cracking. Impact strength is also known as a toughness and is commonly expressed in Joules per meter (J/m) or foot-pounds (ft-lbf).

It’s extremely necessary to learn about this mechanical property because whatever type of metal you get will be subjected to impacts and collisions, even if it’s unplanned. Everyday examples of impact stresses include stamping dies and chisels or a hammerhead colliding with an object.

Understanding these properties will give you a better idea on which type of metal will work best for your project. You can also ask your steel manufacturer for advice and recommendations.