GTP Schäfer

GTP-Schäfer is one of Europe’s leading manufacturers of exothermic and insulating risers and sleeves. Ever since the company was founded in 1988, it has rigorously pursued the ongoing development of its innovative product portfolio in order to offer foundries the broadest possible spectrum of solutions. The portfolio comprises several hundred types of risers covering a broad scope of modulus and applications. GTP Schäfer deploys a 3-shift operation system, manufacturing its high-quality riser systems with a workforce of about 80 people in Grevenbroich, Germany.


The portfolio is including the whole range of exothermic and insulating materials, risers and sleeves which are selected purposefully by foundries seeking an increase in productivity and an overall improvement of the casting quality. In order to prevent the final piece from shrinking, risers should be designed in such a way that the solidification module is larger than that of the junction to the cast piece. Due to the larger solidification module, the riser keeps the metal contained inside longer in a liquid state, thus providing time to balance the volume deficit in the solidification phase of the piece. In this way, the final point of solidification occurs within the riser and the sealing of the cast piece is ensured.

CellMark Metals knows exactly how to calculate the best riser for each application and every type of casting and this in relation to the moulding system or sand used.