Jominy end-quench test

The end-quench test is a simple hardening test. You take a cylindrical specimen, heat it, and quench it at the end face with a defined water jet. Then you measure hardness along the length of the specimen. This shows you how well the material can be hardened and how deep the hardening reaches. That's important for welding because you can see if the heat-affected zone tends to harden and if you have to expect cracks. Depending on the result, you know whether you need to preheat or control cooling differently.