One of the limitations of physical and plasma-assisted chemical vapor deposition (PVD and PACVD) technologies is their inability to deposit coatings into inner surfaces, like holes and cavities with a high aspect ratio. Chemical vapor deposition (CVD) technology, however, allows coating of inner surfaces of virtually unlimited length and aspect ratio. This is achieved by management of reactive gas flows, a technique mastered by Ionbond engineers on many different products. High-quality coatings such as TiN, TiCN, ZrN or Al2O3 can be produced on inner diameters of various geometry, size and length. The CVD process is especially friendly for austenitic (300 series) steels, which are unaffected by high temperature of the deposition process. Other materials may or may not need an additional heat treatment after processing, depending on the application requirements and their composition. Ionbond engineers have developed several solutions for successful protection of IDs against wear and corrosion with CVD-produced coatings.