The IDMT_ISA_METAL_BALLS dataset contains sound files of three differently coated types of metal balls running down a metal slide (K1, K2, K3). The different surfaces cause a hearable difference of the rolling sounds, which we consider as indicator regarding the condition of the coating. The dataset was created using a low-cost microphone as sensor. Industrial background noise was played via external loudspeakers during the recording process for simulating a realistic acoustic environment. We provide both an unbalanced split, which resulted from the original recording process, with a total size of 2267 recordings as well as a balanced split for reproducibility of experiments. Two additional test sets with more than 250 recordings each are provided where general settings like the angle of the slide and the position of microphone have been altered for testing the robustness of the system to changes in the setup. File duration: 18.87 minutes # K1: 987 # K2: 1198 # K3: 647 # Total WAV Files: 2832 Sampling rate: 44.1KHz Resolution: 32-bit Mono audio