A letter-shaped fastener is a type of hardware used to join two or more objects together. The most common types of letter-shaped fasteners are tnuts, tbolts, and ubolts. Tnuts are four-letter fasteners that have a threaded hole in the middle and are used to attach a nut to a surface. Tbolts are five-letter fasteners that have a head on one end and a threaded shaft on the other end, and are used to secure two or more objects together. Ubolts are also five-letter fasteners that have a U-shaped base and a threaded shaft, and are used to attach a pipe or rod to a surface.