Archaeological iron artifacts are often boiled in water to remove corrosion-causing chlorides as part of a conservation effort. Quenched steel (i. e. martensite), however, can be softened and the grain structure slightly altered by extended boiling. Thus, the boiling of quenched steel archaeological artifacts could affect important structural data and could bias future research. This study investigates the effects of boiling martensite as identified by optical metallography and Vickers hardness testing, two methods commonly utilized in archaeometallurgical studies. 30 non-quenched steel discs (controls) and 30 quenched steel discs were boiled, with both an unquenched and a quenched disc being removed at regular time intervals. The maximum duration of boiling was 20 hours. The discs were metallographically examined and their hardnesses were measured before and after boiling. Boiling did not visibly disturb the grain structure of martensite, but did reduce the hardness of the metal from an average of 849.0 ± 3.4 HV/500g prior to boiling to an average of 803.6 ± 3.4 HV/500g after boiling. For the annealed discs, there was no alteration in the grain structure, and the hardness of the metal only decreased from 163.2 ± 0.5 HV/500g on average before boiling to 162.0 ± 0.5 HV/500g on average after boiling, which is negligible for Vickers hardness measurements.