This document specifies the characteristics of reverse-taper grooved pins with one quarter-length progressive grooves on both sides (with closed ends), in steel and stainless steel, and with nominal diameters 2 mm to 25 mm. These grooved pins are designed to fulfil the main following functions: relative rotation of the assembled parts, and locking of two (or more) parts, with an easy installation due to its symmetrical shape and a medium level of pull-out resistance due to the elastic fit behavior of the pin. The general requirements (including functional principles for grooved pins and assembly) are specified in ISO 13669.