Raw data for "Exchange scaling of ultrafast angular momentum transfer in 4f antiferromagnets" The h5 files are provided: 1. Windsor_LnRh2Si2_2022_static.h5 This file provides the temperature dependences of the 4f moment, as collected from the (001) magnetic reflection (details described in the supplementary materials, section 1.1. The file is divided by Ln ion, for each LnRh2Si2 material. For each material the sample temperature and the moment (normalized) are given. 2. Windsor_LnRh2Si2_2022_dynamic.h5 This file provides the delay dependences of the 4f moments, as collected from the (001) magnetic reflection (details provided in the methods section). The file is divided by Ln ion, for each LnRh2Si2 material. This is further divided into datasets that correspond to different pump fluences. For each fluence the fields provided are the moment (normalized), the corresponding error (see methods), the delay, and the fluence value.