The present invention provides a novel die assembly for extruding and drawing ferrous and non-ferrous metal, and also to a method of making the same. The die assembly according to the present invention comprises a die core (3); at least one pre-stressed ring (2) placed around the die core (3); and a die casing (1) surrounding the ring (2), wherein the ring (2) is plastically deformed and hardened by press fitting it to the casing (1) so that the ring has compression stress exceeding its material yield limit by 10-40%, and the mating geometric feature (5) of the core and the ring is tapered towards the exit, to thereby obtain a rigid container system in which a die core can be press fitted with a great force without die cracking. As a result, a long lasting die assembly with surprisingly high performance, small dimension and low production cost is obtained by assembling the die core by a great force without die cracking.