Nut and bolt assembly - has plain spigot or bore to aid alignment and prevent faulty thread engagement

摘要

In a nut and bolt assembly, either the bolt has at its tip a plain locating spigot, whose diameter (d1) is equal to the thread core diameter, or the nut has at one end a plain bore, whose diameter (d) is equal to the thread nominal diameter. The length of the plain spigot or bore is > the thread pitch. This arrangement ensures that the nut and bolt are aligned correctly as assembly, thus preventing faulty engagement of the threaded portions.