Because of this small clearance and the high wire speeds the guide tip is subjected to
substantial wear. Therefore, it is often made with inserts made of diamond, aluminum
silicate or hard metal alloys [33, 125]. The centering of the die ring is done by bolts.
Only very small adjustments of the melt flow are necessary when the dies are properly
designed because the throughput changes exponentially with the gap width by a power
of up to three.