Extended brass nozzle, default 0.4 caliber.
Clogging, wear caused by abrasives, or the need for a new nozzle of a different size.
socket tool
open end wrench
new nozzle
If there is any residual material in the nozzle, heat the hot end to melt the material.
Pay attention to the high temperature when replacing it to avoid burns.
Check the fixed heating block after replacement to prevent it from loosening during the nozzle replacement process.