Tensile Strength: A Basic Guide and Explaination

The simplest definition of a metal strength is that it's the ability of material to resist external load. The most common representation of  metal strength or and say the most commonly used form of material or metal strength is the metal tensile strength.

What is tensile strength of metal

The tensile strength of metals is the ability of metal to resist against the tensile load. The tensile load is the pulling force acting on a body along its longitudinal axis / direction. 

When a tensile load is applied to any product or workpiece, that tensile load creates tensile stress in it. And the ability of any product or workpiece to withstand tensile stress is called metal tensile strength.

Tensile strength Definition

The tensile strength of metals can be defined as the metal's ability to resist a specific magnitude of force on its unit areas. It is measured as Newton per unit meter square also known as Pascal.

It is important to mention here that pressure, stress and strength all have the same expression, formula and unit of measure but they represent different conditions and features of a product.

Why is metal tensile strength important?

As we have stated, the tensile strength of metals is the tensile stress capacity of any metal so whenever a meter is converted into a product and that is used for a machine or any work. 

If so, the external stress is applied to it and if that stress exceeds the tensile strength, it leads to metal failure, which can cause total product failure.

Therefore, before selecting the material for any product, it is very important to study the metal tensile strength of the material, take it into consideration and make decisions based on this during material selection.

Understanding metal tensile strength is crucial for applications like deep drawing aluminum or deep drawing brass, where materials are subjected to significant stresses during the forming process.

Different types of Tensile strength

There are two basic types of materials in the world, one is ductile and the other is brittle. Brittle materials are those that do not show elastic deformation at all and fracture immediately whenever the external stress exceeds their strength.  

In contrast, ductile materials are those that exhibit both elastic and plastic deformation. And when an external load is applied to them, they first show an elastic deformation and then a range of permanent plastic deformation before fracture.

For your information, elastic deformation is the deformation in which the material returns to its original shape after removal of the stress, on the contrary, plastic deformation is the deformation in which the material does not return to its original shape after removal of the stress. It does not spring back into shape and any deformation that occurs is permanently reflected in the material.

In this sense we can divide the tensile strength of materials into two basic types. The first is the material yield strength and the second is the material's ultimate tensile strength.

Metal Yield Strength

Metal yield strength is the type of tensile strength that represents the extent of metal before which the material shows elastic deformation.

The yield strength of a material is up to a certain limit and this limit is called the yield point i.e. the initial strength of the material before the yield point is called this strength and the initial deformation of the material before this point is called yield strength. is called elastic deformation

Elastic deformation is a temporary deformation and as soon as the external stress is removed, the deformation is removed and the material returns to its original shape.

Metal Ultimate Tensile Strength

Ultimate tensile strength of a material is the type of tensile strength of metals that indicates the maximum strength of a material beyond which the material cannot withstand a greater stress than it can withstand if a greater stress is applied to the material. So the material fractures and breaks into two parts

When an external stress is applied to a metal, elastic deformation remains in the metal up to the yield point, and beyond the yield point, plastic deformation begins. The process begins and after a few moments the material undergoes fracture.

These concepts of yield strength and ultimate tensile strength are particularly important in processes like custom precision metal stamping for medical devices, where maintaining precise dimensions and material integrity is critical.

Which type of tensile strength is more important?

We have studied two types of tensile strength of metals, the yield strength and ultimate tensile strength but which of them is more important. All of this depends on two things, the first is what type of material you are using, whether you are using a ductile material such as steel or a brittle material such as cast iron.

This is because ductile materials such as steel have both yield tensile strength and ultimate tensile strength, brittle materials have only ultimate tensile strength.

So if we are using a ductile material we can consider both the ultimate tensile strength and the yield tensile strength whereas if we are using a brittle material we can only consider the ultimate tensile strength.

Secondly, what are the requirements of the material you are selecting for this product? If the product requirement is that the product maintains its shape, size and integrity, it is better to consider the yield strength of the material. Be aware that material deformation beyond the yield strength of the material can lead to permanent product failure.

On the contrary, if the product requirement is such that it does not matter much about permanent information, then the ultimate tensile strength of the material can be taken into account.

How to determine metal tensile strength

There is only one way to determine the tensile strength of metals and that is to subject the metal to a tensile test. Tensile test is a test in which a metal sample is prepared which can be either round cross section or square cross section according to the test standard.

A sample of metal is taken and fixed in the joints of the machine and the machine is started. The machine continues to apply tensile stress to the metal sample until the metal sample fractures in two.

The stress at which the metal sample fractures in two is recorded by the machine and is the ultimate tensile strength of the metal sample. The machine on which this test is performed is called an ultimate tensile testing machine and modern machines have the facility to show the yield point, ultimate tensile strength point and fracture point of the metal on a graph.

Modern tensile testing machines can often be programmed to perform specific test protocols, which is particularly useful for custom stamped components that may require unique testing parameters.

Different strength types of metal

Along with tensile strength in any metal, tensile strength also counts as the metal product is not only subjected to tensile stress but also various types of stresses such as compression stress, bending stress, shear stress.

Therefore, for each type of stress, the material has a specific strength that gives it resistance against that particular stress. Apart from tensile strength, three types of metal strength are as follows

•  Metal Compression Strength

•  Metal Bending Strength

•  Metal lion strength

Metal Compression Strength

Metal compression tensile strength is the reverse of metal tensile tensile strength in that the metal is compressed longitudinally at both ends until it buckles and fractures in two.

The ability of a material metal to resist this compressive stress is called the metal compressive strength.

Metal Bending Strength

Whenever a metal workpiece is supported on both sides and an external load is applied in the middle of it to try to bend it, the ability of the material to resist that particular bending stress is called metal bending strength. Is

Metal Shear Strength

Metal CS is the property of the tenth metal that gives it the ability to resist shear stress. Whenever a metal is subjected to a stress that tends to shear it, the strength of the metal that resists shearing is called metal shear.

List of yield strength and tensile strength of different metals

Below is a table listing yield strength and ultimate tensile strength for various metals, including different types of steel. Please note that the values provided are approximate and can vary based on factors such as material processing, composition, and testing methods.

Concluding the Tensile Strength of Metal

Tensile strength is one of the most important  mechanical properties of any metal.  It's very important to consider the tensile  strength of metal during the material selection face of any product. This is because if external stresses go above the ultimate tensile strength of a metal then this can lead to total product failure.