> For the complete documentation index, see [llms.txt](https://ms-kb.msd.unimelb.edu.au/next-lab/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ms-kb.msd.unimelb.edu.au/next-lab/3d-printing/open-access-printers/prusa-open-access/support/worn-nozzle.md).

# Worn Nozzle

![Image from MakeZine](/files/-MS_GxABMLdGHNCYDmAW)

Nozzle wear occurs when the diameter of the orifice becomes wider (in this case, >0.4mm) or no longer becomes round. These typically happen on brass nozzles and are caused when abrasive filaments such as carbon fills, wood fills and metal fills are used. A worn nozzle leads to unpredictable extrusion and print finishes as the extrusion is based off a round orifice with a set diameter of 1.75mm.

**When is it a good time to change your nozzle? Read more about it here:**

{% embed url="<https://3dprinterly.com/when-how-often-should-you-change-your-nozzle-on-your-3d-printer/>" %}