This document specifies the characteristics of grooved pins with half-length centre oval grooves (with closed ends), in steel and stainless steel, and with nominal diameter 1 mm to 25 mm. These grooved pins are designed to fulfil the main following functions: — relative rotation of the assembled parts, and — positioning or guiding, with an easy installation (due to its symmetrical shape) and a high level of pull-out resistance (due to the elastic fit behaviour of the pin). The general requirements (including functional principles for grooved pins and assembly) are specified in ISO 13669.