In 1987 Schäfer founded the rock band Fury in the Slaughterhouse together with Kai and Christian Wingenfelder, Rainer Schumann and Christoph Stein-Schneider. He played the bass in this band until 1996, when he was followed by Christian Decker. Together with his band Schäfer was awarded golden recording sales certifications for the Fury albums "Fury in the Slaughterhouse" (1988), "Mono" (1992), and "the Hearing and the Sense of Balance" (1995). Fury in the Slaughterhouse sold about three million recordings of albums made in their time with Hannes Schäfer (1987-1996).