A joint research project of the Institute of Ferrous Metallurgy, RWTH Aachen University; the Institute of Materials Science and Engineering, Kaiserslautern; the Gear Research Centre, Munich; and the Foundation Institute of Materials Science (IWT), Bremen, named “HiPerComp: High Performance Components,” resulted in new damage-tolerant steels for rolling bearing and gear applications. The main target of the project was the introduction of strengthening mechanisms and localized plasticity to common through-hardening bearing and case carburizing grades. These microstructural-based mechanisms were expected to reduce the sensitivity against nonmetallic inclusions and by that increase the bearing life. For a 52100 bearing steel, an aluminum addition of up to 2 mass% should develop the capability of transformation-induced plasticity effects as well as a further strength increase by k-carbides. For case-hardening grades such as ISO 18CrNiMo7-6 (comparable to AISI 4820), a copper addition was investigated, which can lead to the formation of coherent copper clusters, thus increasing the strength. Although the new alloys were developed at the Institute of Ferrous Metallurgy, the new heat treatments were investigated at IWT. At the Institute of Materials Science and Engineering, a new approach in high throughput fatigue testing methods (“Phybal”) was evaluated in these material conditions to discover the most promising combinations. The gear grades finally were tested as real gears at the Gear Research Centre while the most favorable bearing steels were tested as deep groove ball bearing inner rings at IWT. This paper will cover the investigations on 52100 bearing steel. At high loads, the new alloys showed equivalent lifetimes compared to industrial bearings. Yet the improved damage tolerance was revealed in testing conditions with lower loads (2,800 MPa Hertzian stress) with artificially damaged inner raceways. The best alloy and heat treatment combination of aluminum-alloyed 52100 steel achieved a 16 times longer life.