Locknut 0201203 is an axial fixing component used to secure the bar guide bushing on the Feed finger tube of the Gildemeister DMG Mori GM20AC multi spindle automatic lathe in the 20 mm bar configuration. Its main function is to keep the guide bushing correctly positioned relative to the drawtube, ensuring centering of the bar during rotation and feeding while contributing to the absorption of vibration generated by the moving material. Within the bar feeding system, the locknut works together with drawtube 1501351, the bar pusher collet, the 6206 RS bearing, locknut 0201202 and pad 0801017, creating a stable assembly with coherent kinematic behavior. When the cam drive produces axial displacement of the drawtube, the guide bushing must keep the bar properly supported to prevent bending, oscillation and irregular contact that could compromise feeding precision and the quality of the turned part. Locknut 0201203 therefore provides a reliable axial reference for the bushing and helps maintain constant guiding conditions even in continuous and highly repetitive cycles. In industrial use it is especially important in automotive production, precision engineering, quality control and maintenance of multi spindle lathes, where bar stability, reduction of backlash and cycle continuity have a direct effect on productivity. During maintenance it is advisable to check the tightening of the locknut, absence of play in the guide bushing and smooth sliding of the drawtube, because insufficient fixing can increase vibration, form errors, surface marks and dimensional variation. Locknut 0201203 is therefore a mechanical setting and safety element of the bar feeding system, essential for ensuring precision, reliability and reduced dynamic stress on the rotating bar.