This data set contains the data of single grain crushing tests. Tested were two types of sand, which are used to increase friction in wheel-rail contacts. Please see the following paper for a detailed description of experiments: " Suhr, B.; Skipper, W.A.; Lewis, R.; Six, K. Sanded Wheel–Rail Contacts: Experiments on Sand Crushing Behaviour. Lubricants 2023, 11, 38. https://doi.org/10.3390/lubricants11020038 " Two types of experiments were conducted, both of them were single grain crushing tests. First, initial breakage tests were conducted. Second, single grain crushing tests were conducted under realistic wheel-rail load including subsequent grain/fragment crushing. The material tested was two types of sand used in railways, called AT sand (used in Austria) and GB sand (used in the UK). Both types of sand are tested under dry and wet contact conditions. Please see the referenced paper for details on the conducted experiments.