Induction hardening, although a safe repeatable process, can require a lot of tuning whenever an input parameter or inductor is changed. This paper discusses the nature of the problem and how it can be alleviated using 3D technology. It explains that long setup times and tedious adjustments after tooling changes are due to inaccuracies in the inductors and their positioning relative to the workpiece. It then describes how these inaccuracies are removed using 3D construction, production, measurement, and positioning technology, including FEA and CFD software, laser powder bed fusion, and optical scanning. To verify the approach, two inductors were additively manufactured and tested in a hardening system. The first inductor was used to harden a bearing seat on a shaft. The inductors were then swapped and another part was hardened without any adjustment to the process. The hardening depth and surface hardness of the two parts are identical within the scope of measurement accuracy.