PURPOSE: To supply a hot extruding die high in hardness and excellent in wear resistance by welding power sintered high speed steel to form the tip part of a mandrel.

CONSTITUTION: In a die for manufacturing tube stock composed of Al, Cu, etc., by hot extrusion, the tip part of the mandrel to form the internal diameter of the tube stock is arranged by frictional welding, then, undergoes hardening and tempering. The powder sintered high speed steel is composed of C; 1.00-2.20%, Cr; 3.80-4.50%, Mo; 2.00-7.00%, W; 6.00-15.00%, V; 2.50-6.50%, Co; 7.00-13.00% and Fe; the balance. As occasion demands, P≤0.030%, S≤0.030%, C≤0.25% and Ni≤0.25% are contained. By this method, the life of the die is extended by twice or more and the quality of a product of tube stock is improved.