Terminal crimping apparatus

A terminal crimping apparatus, comprising:

• an anvil for supporting a metal terminal including a base plate portion for placing an electric wire thereon and a pair of crimping piece portions extending upwardly respectively from opposite side edges of the base plate portion;
• and
• a crimper which includes an opening portion and a press-fastening portion having a generally arch-shape formed of two arc-shaped surfaces which are opposed to the anvil,
• wherein the anvil and the crimper cooperate to press-fasten the crimping piece portions for crimping the crimping piece portions to the electric wire placed on the metal terminal;
• and
• wherein a radius R of curvature of each of the two arc-shaped surfaces of the press-fastening portion of the crimper is determined so as to satisfy the following formula:
• 0.25 W≦R≦0.27 W
• where W represents a predetermined width of a crimped portion of the metal terminal to be formed;
• and
• wherein a width of the opening portion of the crimper is equal to the predetermined width of a crimped portion.