The heat-treat process-verification articles included here are what we call “evergreen.” This simply means that they are applicable and useful well past the magazine print date. These articles have stood the test of time, and readers continue to show their interest through online viewing.


Understanding the Jominy End-Quench Test

Regardless of the category, this article just might be the most-read in Industrial Heating history. In fact, it was originally published in September of 2001, but heavy reader interest led us to bring it back in May 2015. Author James Marrow had moved to the University of Oxford in the intervening years, but we located him and updated his contact information in the 2015 version.

The article deck helps us understand what is covered. It states, “The Jominy end-quench test is used to measure the hardenability of a steel, which is a measure of the capacity of the steel to harden in depth under a given set of conditions. This article considers the basic concepts of hardenability and the Jominy test.” 

What follows is a great discussion of hardenability principals followed by how the test works. It is concluded with the effects of various alloying elements on the hardenability of the steel alloy. You can find this article at


Are You Measuring the Correct Temperature?

Sometimes popularity can be more affected by “newness,” which might be helping this article a bit. It was published in May 2016, and readers seem to appreciate what it has to say. Again, the article deck gives us the lowdown: “Noncontact temperature measurement is a key process metric in many industries, but there are many factors that influence accurate temperature measurement from a pyrometer. Here we look at the common influences on inaccurate temperature measurement.”

One of the key discussion points is what wavelength detector is best for a given application. Emissivity and calibration are also key areas of information. If you use noncontact temperature measurement for your process, this would be a good article to read. You can find it at


Hot Tensile Testing – Improving Efficiency

I’m not sure how many readers actually do elevated-temperature tensiles, but this article caught your interest. The setup basics of this test are discussed, including the fact that it is a time-consuming process due to the heating time of the sample.  The key discussion involves the use of a carousel system to improve the efficiency of the process. With the carousel, an entire shift worth of testing can be done in the time it previously took to test one sample. 

This article originally appeared in our April 2014 magazine, but it was rerun online in February 2015. You can find it at


Difficulties Using Standard Chart Methods for Rating Nonmetallic Inclusions

This article was written by one of the preeminent metallographers of our day, George Vander Voort, and originally ran in the January 2016 issue. Reader interest is no doubt due to the fact that many of us are required to evaluate material for inclusions. I would like to have a dollar in my pocket for every hour involved (in a former life) in JK testing.

Vander Voort discusses the history of the test and advances in the technology. He also discusses the challenges and includes a round-robin interlaboratory test conducted to demonstrate those challenges. You can learn more by reading the article at


The Ellingham Diagram: How to Use it in Heat-Treat-Process Atmosphere Troubleshooting

Originally published in April 2011, this article has become one of our readers’ all-time favorites. I think this one struck a chord because it practically applies something from our thermodynamics days to our everyday heat-treating experience. Believe it or not, the article discusses Gibbs Free Energy, enthalpy and entropy. 

The author provides practical examples of how to use the diagram, particularly for heat treating. I encourage you to check out why this article has such a loyal reader following by using the following link:


Composites Testing for Aerospace Applications

Part of our regular aerospace coverage, this article originally ran in November 2015. The aerospace experts at Westmoreland Mechanical Testing & Research discussed the need for testing composite materials. Did you know that half of the Boeing 787 and Airbus A350 are constructed of composite materials? Needless to say, we want reliable testing of the planes in which we fly.

This popular article discusses a range of testing, which includes tensile, compression, shear, fatigue, thermal analysis and multiple physical properties. Check it out ( to learn more.


Hardness-Testing Machine Shopping Tips

Shopping for any equipment for our facilities can be challenging. This is likely the reason this article has been so popular with readers. It helps us figure out what we need to look for when shopping for hardness testers. The different hardness scales are discussed as well as portable options. 

The article approaches the subject from the perspective of the authoring company, Tinius Olsen, but it is very objective. Published in August 2016, you can find this recent readers’ favorite here:


Impact Testing

In addition to our technical articles, another great source of applicable technical information is The Heat Treat Doctor columns by Dan Herring. A great example of this is a series on impact testing that has garnered much reader interest. This three-part series ran in August, September and October 2015. 

The basics of brittle fracture are discussed along with specific information on the Charpy and Izod impact tests. It’s a great summary of this type of testing, which even includes a discussion of how to compare Izod and Charpy impact values. You can find the first part here:


While these articles are not the only evergreen content available on our website, they are great examples of editorial information that interests readers long after their original publication date. And that’s one of the benefits of our website. Articles back to the turn of the century are preserved for your reference. That’s a treasure trove of great information, and it is just a search away. Happy hunting!

This artically originally appeared in the May 2017 issue of Industrial Heating as Top Testing Topics.