How the Tensile Strength vs. Yield Strength of Metals Affect Their Use

It’s important to analyze the different mechanical properties of any metal before considering its application for a project. In this regard, tensile strength and yield strength are two of the most important properties to consider, as they offer deep insight into a material’s ability to withstand stress with and without going into permanent deformation.

Below, we briefly describe tensile strength vs. yield strength and how these values can affect the structural integrity and fabrication of different metals.

Tensile Strength vs. Yield Strength

Let’s dive a little deeper into the differences between tensile strength and yield strength and the effects they have on metals.

Tensile Strength

The maximum tensile stress that a material can handle before rupturing is known as its tensile strength. Beyond this limit, the material develops necking and breaks into pieces.

While talking about tensile strength, a material’s ductility may also be of interest. A ductile material can deform more than a brittle material can before it fractures.

Yield Strength

Yield strength represents the maximum stress a material can handle without going through any plastic deformation. This is represented as the yield point on the stress-strain graph, as shown below.

As you can see from the graph, for small strains, the deformation is elastic. It continues until the force reaches the proportional limit (point A) and reverses if the load is removed before that point.

From point A to B, small stress generates a large strain—the first deviation of the curve from linearity. If the stress is more severe, the shape is partially recovered.

After the upper yield limit (B), the material loses its elasticity and enters the zone of plasticity. The level of stress that causes appreciable plastic deformation is called yield stress. Further increase in the deforming force ultimately leads to material failure.

The nature of permanent deformation is dependent on the material type.

For some ductile materials, such as copper and aluminum, it is impossible to acknowledge an exact yield point, as the metal can stretch over a high-stress value. In such cases, drawing a parallel line to the initial linear portion of the stress-strain curve but offset from it by 0.2% gives us the maximum stress value, also known as the proof of stress.

The table below compares tensile strength vs. yield strength, which is applicable for any metal in general.

The Importance of Tensile Strength and Yield Strength in Metals

Analyzing the tensile strength vs. yield strength of a metal becomes essential under the following scenarios.

Acknowledging Structural Integrity

The tensile strength and yield strength of a metal decide its areas of application. In the case of larger projects, such as in the aerospace or construction industries, these factors are a matter of life or death. Designers make sure that the maximum stress never reaches the yield strength of the metal used. On the other hand, the ultimate tensile strength tells us the maximum force the metal structure can handle before it collapses.

Metal Fabrication

Metals are checked for strength and ductility throughout different phases of a product life cycle. The upper load limit (yield strength) describes a metal’s behavior during various fabrication processes, including pressing, rolling, and forging. The ultimate tensile strength sets the maximum load limit for the product beyond which it may lose any important property due to permanent changes to the metal’s crystal structure.

Testing for Super Alloys

It is easy to use yield strength as one of the parameters to test a superalloy. Unlike a general metal alloy, a superalloy displays high yield strength at high temperatures. Thus, they are preferred for high-strength applications.

Tensile Strength vs. Yield Strength of Different Metals

Let’s compare the tensile strength and yield strength of some commonly used metals.

Metals with high tensile strength and yield strength come with machining challenges. For instance, tungsten has the highest tensile strength of any other metal. However, it becomes very brittle at room temperature and is subjected to unwanted chipping. Special heat treatment methods must be used to produce a conducive machining environment. Having an experienced metal service provider by your side can help you overcome all these hassles with ease.

High-Quality Metal Services From a Reputable Supplier

At Industrial Metal Service, we have more than two decades of experience offering a wide range of new and verified remnant metals—including stainless steel, aluminum, titanium, and more—to our customers in the San Francisco Bay Area and beyond. We’ve earned our reputation as a reliable and trustworthy metal supplier and service provider, and we want to make sure you have the best materials for all types of welding and other fabrication processes.