This data set contains photos and measurement data from spherical indentation tests on R260 rail steel. This data set belongs to the following journal article: Bettina Suhr, William A. Skipper, Roger Lewis, Klaus Six:DEM modelling of surface indentations caused by granular materials: application to wheel–rail sanding,Computational Particle Mechanics, 2024,https://doi.org/10.1007/s40571-024-00816-w A flat specimen made of the R260 rail steel was indented by a stainless steel (AISI 440C) ball bearing of 8.73 mm diameter. The following normal loads were applied for indentation tests: 100 N, 500 N, 1000 N, 2000 N, 3000 N, 4000 N, 5000 N, 6000 N, 7500 N. For each load level, two tests were conducted to check the repeatability of the measurement. After tests, the indent was analysed using the Alicona InfiniteFocusSL 3D optical profilometer. The Alicona captured a 3D scan covering a 3.66 mm x 3.66 mm area (vertical resolution of 500 nm). Available data and file naming conventions For the test at 100 N load, the available files are named as follows: 11-32__100N.jpg: image coloured by the indentation depth11-32__100N_Diameter.jpg: image of the indent with visually measured diameter of the indent11-32__100N.txt: point cloud of the analyzed surface The repetition measurements’ files at 100N load are named: 11-32__100N_a.jpg, 11-32__100N_Diameter_a.jpg, 11-32__100N_a.txt The files belonging to test with higher applied load are named accordingly. This research was funded in whole, or in part, by the Austrian Science Fund (FWF) project P 34273: DEM modelling of adhesion in sanded wheel-rail contacts. This work was conducted at Virtual Vehicle Research GmbH in Graz, Austria. The authors would like to acknowledge the financial support within the COMET K2 Competence Centers for Excellent Technologies from the Austrian Federal Ministry for Climate Action (BMK), the Austrian Federal Ministry for Labour and Economy (BMAW), the Province of Styria (Dept. 12) and the Styrian Business Promotion Agency (SFG). The Austrian Research Promotion Agency (FFG) has been authorised for the programme management.