This dataset provides friction data from ring-shear test (RST) on a plastic (polyester) sand material that has been used in flume experiments (Marra et al., 2014; Kleinhans et al., 2017) and is now used in the Tectonic Laboratory (TecLab) at Utrecht University (NL) as an analogue for brittle layers in the crust or lithosphere. Detailed information about the data, methodology and a list of files and formats is given in the data description and list of files that are included in the zip folder and also available via the DOI landing page. The material has been characterized by means of internal friction coefficient and cohesion as a remote service by GFZ Potsdam for TecLab (Utrecht University). According to our analysis the material behaves as a Mohr-Coulomb material characterized by a linear failure envelope and peak, dynamic and reactivation friction coefficients of 0.76, 0.60, and 0.66, respectively. Cohesions are in the order of few tens of Pa. A minor rate-weakening of 3% per ten-fold rate change is ...