The most direct method to identify 4140 is to use a portable spectrometer, which can quickly and non-destructively detect the main alloying elements and their approximate content, but it cannot measure the most important non-alloy element, carbon content.
The most accurate method: laboratory wet analysis, which provides the exact percentage of all elements.
In addition, some material identification can also be done directly or indirectly by observing sparks and testing hardness.Learn More