The RILEM TC 304-ADC has set up a large interlaboratory study on the mechanical properties of 3D printed concrete (ILS-mech). The study was prepared in 2022 by a preparation group leading to a Study Plan which the TC approved on 29 November 2022 (https://doi.org/10.14459/2023mp1705940). The ILS-mech was performed in 2023. The data was collected using a pre-prepared spreadsheet template. For data management, a database was derived and set-up in openBIS. The underlying Postgres database of openBIS was exported to the here-published SQLite database for sharing without maintaining a server. The structure of the database is described in (https://doi.org/10.1617/s11527-025-02650-9). The results are discussed in three associated papers focusing on the overall outcomes and evaluation of the procedures (https://doi.org/10.1617/s11527-025-02686-x), the compressive test results (https://doi.org/10.1617/s11527-025-02688-9), and the tensile test results (https://doi.org/10.1617/s11527-025-02687-w). contact via freek.bos@tum.de