PURPOSE: To eliminate the need for a high-precision screw machining, enhance a reliablity, and lower a cost by fastening a tie bar to a die plate by a resilient force of resilient bodies provided on the tie bar.

CONSTITUTION: A tie bar 3 is provided through a mounting hole 2 formed in a first die plate 1. An end part 3a of the tie bar 3 is positioned in a recessed part 15 formed in a first die plate 1. In the recessed part 15, a plurality of resilient bodis 16 of, e.g., ring-form belleville springs having a non-flat shape as a whole to serve as locking rings are provided in a laminated state. The end part 3a of the tie bar 3 is inserted through a center hole 16a of the resilient bodies 16. A retaining ring 18 is provided on the end part 3a through a spacer ring 17. The resilient bodies 16 are contained between the spacer ring 17 and a bottom part 15a of the recessed part 15 in a depressed state.