Terminal fitting and chain terminal

A terminal fitting, comprising:

• a box portion, a mating terminal being inserted into the box portion from front, wherein the box portion comprises an upper wall and a lower wall provided opposite to the upper wall, wherein the lower wall comprises a through hole provided thereon;
• a base portion fixed in the box portion;
• a contact portion arranged forward of the base portion, the contact portion electrically contacting the mating terminal being inserted into the box portion;
• and
• a spring portion provided to link the base portion and the contact portion, the spring portion supporting the contact portion displaceably in an insertion direction of the mating terminal,
• the spring portion being shaped such that a plurality of plate portions elongated in a direction intersecting the insertion direction are folded and linked while being spaced apart in the insertion direction, and
• intermediate parts of both side edges in a longitudinal direction of the plate portion comprising a plurality of curved portions, the plate portion being constricted toward a center from both ends in the longitudinal direction,
• wherein the terminal fitting further comprises a supporting portion, wherein an end of the supporting portion is fixed to the upper wall of the box portion and a tip part of the supporting portion is inserted into the through hole.