The services at Fraunhofer-Center HTL for the testing of inorganic fibers, such as, e.g., ceramic fibers, includes the determination of the sizing content of fiber bundles, the determination of the fineness and the fiber diameter as well as the determination of the mechanical properties of single fibers and fiber bundles at room temperature. Thread and braid abrasion tests are carried out with special equipment, as are mechanical tests (creep, high temperature tensile strength) in inert gas atmosphere up to 1500 °C. In addition, the HTL offers examination methods for the characterization of the thermal stability of ceramic fibers in oxidizing atmospheres up to 1750 °C or in inert or reducing atmospheres up to 2100 °C. Studies of the chemical resistance to acids or alkalis as well as to metallic melts complete the range of services. The HTL tests both in-house and externally developed as well as commercially available ceramic fibers. Further processing of the fibers is carried out using a range of textile processes.