A fishplate, splice bar or joint bar is a metal or composites connecting plate used to bolt the ends of two rails into a continuous track. The name is derived from fish, a wooden reinforcement of a "built-up" ship's mast that helped round out its desired profile. The top and bottom faces taper inwards along their short dimensions to create an even alignment between the two rails when the fish plate is wedged into place by tightening its bolts during installation.