... steel with high resistance to thermal shocks and fatigue, good thermal conductivity, hot tensile and impact strength, resistance to tempering, ... , dummy blocks, pressure pads, bolsters, dies and containers for metal tube and rod extrusion, hot extrusion tools, single block ... inserts, die casting tools, hot forming dies, hot gripper and header dies. Heat Treatment:Annealing : 750 - 800 °CHardness ...