An adjust pin (1) for connecting a plurality of blocks (2) to each other to make up a wrist watch band (3) is formed of a metal with a property having a superelastic region where a stress remains constant against variation in strain. The adjust pin (1) is provided with a bent part (5) for causing a bending stress in the superelastic region to act on the inner wall face of a connecting through-hole (2a) of a block (2) in a state wherein the block (2) is joined with an adjoining block (2). When the adjust pin (1) is inserted in the blocks (2), and the bent part (5) is positioned in the connecting through-hole (2a), the bent part (5) provides a force acting on the inner wall of the connecting through-hole (2a) by the agency of the bending stress in the superelastic region, thereby securely holding the adjust pin (1) by a spring force thereof.