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How To Tell if a 3D Printer Nozzle Is Bad (5 Ways)

It can be frustrating when things go wrong and you're trying to determine and fix the problem. One common issue is with your printer nozzle, but how can you tell it's bad?

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3D printing can be a dream come true if everything’s going right, you can print objects at home using just a few materials! However, it can be frustrating when things go wrong and you’re trying to determine and fix the problem. One common issue is with your printer nozzle, but how can you tell it’s bad?

Here are 5 ways you can tell if a 3D printer nozzle is bad: 

  1. The nozzle diameter has increased. 
  2. You have a deterioration in print quality.
  3. You can see visual deterioration on your nozzle. 
  4. The tip of the nozzle is rounded. 
  5. The plastic bends during an extrusion test. 

To keep enjoying your 3D printer, you need to ensure that all the parts are in order and working correctly. If your 3D printer nozzle is causing problems, read on as we discuss the different tell-tale signs and what you can do about it in detail. 

1. The Nozzle Diameter Has Increased

If the nozzle is getting old, the diameter can increase, which can cause low-quality 3D prints. If you cannot visually notice a difference, you can check using a set of drill bits.

If you bought a 0.5 mm diameter nozzle and can fit a 0.6 mm diameter drill bit into the hole, the diameter has increased.

I like using the 3D Printer Nozzle Drill Bits from for this because the drill bits are tiny enough to determine if the nozzle diameter has changed in size. It also comes in 10 different sizes, so I have any size I need.  

drillbits 3d printer nozzle

2. You Have a Deterioration in Print Quality

If your print quality has gone down and you’ve checked everything else, there’s a good chance your nozzle is in bad condition. Nozzles are consumables, so you’ll have to replace them many times in your printer’s lifespan

You generally need to replace your nozzle every 3-6 months, but this depends on how often you use your printer, the kind of filaments you use, and the quality of the nozzle. 

If you’re looking for a good set of nozzles, I like the Luter Extruder Nozzles from These nozzles are brass, so they won’t last as long as steel, but they’re high quality and easy to install. The set also comes in various sizes, so you’ll have the nozzle you need for any printing job.   

If you want something a little more durable than brass but still affordable, I recommend stainless steel nozzles. These Kingroon 3D Printer Nozzles from are high-quality stainless steel and are easy to install and change. The steel is heavy-duty, so these nozzles will most likely last longer than brass nozzles. 

3. You Can See Visual Deterioration on Your Nozzle

If you can see wear on your nozzle, that’s a pretty clear indicator that the nozzle is bad and should be replaced. This kind of damage comes from regular use and is unavoidable. If the nozzle has bumps or grooves, this will impact its ability to layer consistently.

If you start noticing blobs or bumps on your 3D prints, this is likely due to the physical wear of your nozzle. Another sign of this kind of damage is your nozzle dragging into your prints, which can be incredibly annoying if it’s a print lasting several hours.

4. The Tip of the Nozzle Is Rounded

The tip of your nozzle should be sharp, and if you notice it’s more round than normal, your nozzle is near the end of its life.

Abrasive materials can cause the tip of the nozzle to become less sharp, especially if you’re printing with these materials regularly. 

A round tip leads to adhesion issues, as the height of the nozzle and the bed of your printer will be off-balance. There’s no way to fix a round tip; you’ll just need to replace the nozzle.

If you’re typically using abrasive materials, you may want to consider investing in more durable nozzles. 

Hardened steel nozzles have high wear resistance and are extremely durable. They may cost more than brass nozzles, but you won’t need to replace them nearly as often, so the initial investment may be worth it in the end. 

I like this Mudder Hardened Steel Nozzle from because they have good abrasion and corrosion resistance. They’re extremely precise because they’re smooth and have no burrs. 

If you’re seeking the ultimate nozzle, you can invest in a brass nozzle with a ruby tip, ensuring wear resistance and high-temperature resistance. 

The ruby does make this nozzle more expensive than other kinds, though. This POLISI3D MK8 Ruby Nozzle from is a good choice because it works with a wide range of materials, including nylon, steel, and wood, and it can withstand extremely high temperatures.  

5. The Plastic Bends During an Extrusion Test

One way to check if your nozzle is bad is to do a straight extrusion test. To do this, pull your print head to the side and off the bed. Then, let your printer extruder. If your nozzle is in good condition, you should see a squirt of plastic straight down. 

However, if the plastic is bending or curling, your nozzle is probably damaged and should be replaced right away.

To make your nozzle last longer, you should avoid using abrasive filaments like carbon fiber or glow-in-the-dark filament. Basic filaments, such as PLA, ABS, and PETG are smooth and don’t cause as much damage. Additionally, you can regularly use a filament cleaner sponge and de-gunk your printer to minimize wear on your nozzle.    


Having 3D printer nozzle problems can be a headache, but knowing what to look for ensures your nozzle is in its best shape. 

You’ll know your nozzle is already bad if you see the following signs:

  • The diameter of the nozzle has increased.
  • The print quality has worsened.
  • You can see wear on the nozzle itself.
  • The nozzle’s tip isn’t sharp anymore but is more rounded.
  • The plastic bends or curls when you do an extrusion test.

To prolong your nozzle’s lifespan, avoid using abrasive filaments and invest in better nozzles, such as a brass nozzle with a ruby tip.

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About Ben

I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.