How to Test the Hardness of Stainless Steel Pipe

Hardness tests are typically used to determine the hardness or strength of a given material. This test enables us to define the resistance of a material to scratching, denting, or breaking. It is very much important to know about the hardness of stainless steel pipes. We use this understanding to make sure the pipes are solid enough not to break during their use. Taigang Puxin is a professional Stainless steel pipe manufacturer. Today, we will introduce a more practical method for testing pipe hardness. 

What is Hardness Testing? 

So before we begin testing the hardness of stainless steel pipes, let us understand what hardness testing really entails. Hardness testing is where we press a tool into a material to determine how much pressure it can withstand. The harder the material, the more resistant it is to pressing. There are several common methods used to test hardness, but we will discuss the most common of the hardness tests, Rockwell hardness test. This technique is commonly implemented as it provides straightforward and useful outcomes. 

The Rockwell Hardness Test

So the Rockwell hardness test method really a great way to measure how hard the stainless steel pipes. In this test, two kinds of indenters or indentation tools are used. One is a diamond cone, and the other is a steel ball. Two different loads, which are the amount of applied pressure — minor load and major load — are also applied in this test. We use these loads to determine how hard the steel is. The Rockwell hardness scale is a series from A through C, with C being the hardest level. The Rockwell C scale is what we commonly use for stainless pipe testing because it provides the best information regarding their hardness. 

Classical Method for Rockwell Hardness Testing

So, to check the hardness of stainless steel pipe we actually need a construction cleaning agent called solvent to clean the surface of the stainless steel pipe before doing the final testing. This is helpful because it creates a clean surface to assess and achieve better and reliable test results. After that, we have to get a machine for this job, specifically a Rockwell hardness tester. Again, selecting a proper indenter and load should be based on type of stainless steel under test. We need to ensure the tester is properly configured and calibrated prior to initiating the test. 

Checking the stainless steel pipe to fit on the testing machine. With the pipe being level and centered just below the indenter, it's very critical. We position them this way so that we get the best measurements. And then apply the minor load to create a small dimple in the pipe. This allows us to recover the beginning point, before we are putting further stress. Then we apply the heavy load to get a deeper indent, and measure how deep that indent is. The Rockwell hardness number is calculated by taking the difference between the depth of the indentation under the major load and the depth of the indentation under the minor load. Finally we can refer the Rockwell C hardness number to see how hard it is such as the stainless steel pipe. 

Factors That Can Affect the Test Results

This is why sometimes testing the hardness of stainless steel pipes could also lead to different results. A number of factors may skew the results. The surface finish of a pipe is one factor. This is because we get better and more accurate results with a smooth surface than we do with a rough one. It could result in wrong hardness readings if the surface is poorly finished. The pipe thickness, along with any deformation or alterations to the metal, may also create variations in the output. These transformations can occur during the manufacturing or handling. These are factors that you must keep in mind in order to achieve optimal, accurate results. 

Why Hardness Testing Matters? 

It is important to recognize what hard stainless steel pipes are. It makes sure they are strong enough for the work they are designed to do. If a pipe is lacking in hardness it can be readily broken and bend. This can result in leaks or failures of the pipeline used in this structure. If the pipe is too hard, however, it can be tricky to deal with. It may lack the flexibility needed to fit into tight quarters or to join with other pipes. The hardness of stainless steel pipes can also be tested to verify they are of good quality and will last for a considerable amount of time. 

Testing Hardness: An Important Tool When Working With Stainless Steel Pipes 

Taigang Puxin is determined to deliver the best products for the best possible quality. One of the ways we do this is by testing the hardness of our pipes. We shared some steps to guide you and we hope you can do hardness test on stainless steel pipes confidently. Note to self — be mindful of the variables that can skew the outcomes, and ensure to apply the appropriate testing method for the specific stainless steel grade you are testing. This will help guarantee that the pipes are qualified to be used as they currently are.