Hydrogen embrittlement testing is typically conducted on hardened 4140 low alloy steel. The required stress relief and embrittlement baking temperatures, times and procedures are based upon the heightened susceptibility of this material. Hydrogen embrittlement testing was conducted on carburized 9310 and 52100 to the requirements of ASTM F519 to investigate the susceptibility of these materials as they use lower temperatures for embrittlement baking. The use of higher temperatures would be excessive based upon their respective final tempering temperatures. The test results and the embrittlement behavior of various platings on these alloys will be shared.