How to choose the right nozzle size, material and type for your 3D prints

What Nozzle Size To Choose?

1. Consider the detail level of your application.

Are you aiming to build very detailed or very large parts?
What is the minimum feature’s dimension required?

Nozzle sizes usually refer to the diameter of the nozzle orifice. Sizes from 0.1 to over 2.0mm are available from many manufacturers. The diameter of the orifice has a huge impact on the XY resolution and on the detail of the parts. For instance, a 0.4mm nozzle cannot build geometric features smaller than 0.4mm in the XY plane.
Hence the relevance of the nozzle size regarding level of detail.

2. Consider the part’s mechanical requirements

Is part strength important to your application?
Or rather its low weight?

It is proven that wall and extrusion thickness has a huge impact on the parts’ mechanical resistance to shock or compression. One can either make walls thicker by using more perimeters with a small nozzle at lower extrusion width, or by using less perimeters with a bigger nozzle at larger extrusion width. Due to the filament 3D printing process, consecutive perimeters are printed some time apart, and the cooling down of the previous deposited material will lower the quality of the bonding between them. For that reason, at a specific detail requirement, using bigger nozzles within those requirements and higher extrusion width will deliver stronger parts.

To build lighter parts on the other hand, thinner walls and lighter infill structures are desirable and enabled by “smaller” nozzles.

3. Consider the build speed requirements.

Is build time a relevant constraint to your application?
Or do you have all the time in the world?

Thicker nozzles will allow higher volumetric flow rates and for that reason a faster build speed.
It is important to remember that build speed is a volume related parameter, and only partially dependent on print speed. Meaning, it is possible to build faster at lower print speeds using wider extrusion width and height.

Let's evaluate a simplified example using a small 100cm^3 object and excluding geometrical impacts on time and speed.
Let's consider the hotend has a max volumetric flow rate of 20mm^3/s.
Consider also the layer thickness is 0.2mm and max viable print speed is 100mm/s.
Using a 0.6mm nozzle the required print speed to exploit the full hotend's melting capacity is 180mm/s.
At that speed the print would take about 1 hour and 23 minutes.
Because the speed limit is 100mm/s, the print would actually take 2 hours and 31 minutes.
Using a 1.2mm nozzle the required print speed to fully exploit the hotend capacity is 86mm/s.
And at this speed the print would be completed in 1 hour and 23 minutes.
We built faster at lower speed.
 

All values presented above are subject to approximation

4. Consider the hotend capacity.

Is your hotend capable of delivering enough Volumetric Flow?

As mentioned before, larger nozzle orifices allow more volumetric flow, but its orifice diameter isn’t the only limitation. In fact the limit of how much volumetric flow you can use is defined by the hotend capacity to melt the material.

As an example lets compare a 0.6 and a 1.2mm nozzle using a specific Max Volumetric Capacity. 
Considering a 3D printer, 
capable of delivering a good surface quality at up to 100mm/s,
with an hotend that can melt up to 20mm^3/s,
printing a part using 0.2mm layer thickness,
A 0.6 mm nozzle printing at 0.6mm extrusion width requires 11.14mm^3/s while printing at 100mm/s.
Inside the hotend capacity.
A 1.2 mm nozzle printing at 1.2mm extrusion width requires 23.14mm^3/s while printing at 100mm/s.
Outside the hotend capacity.

All values presented above are subject to approximation

At a standard or pre-defined print speed, the capacity of a nozzle to deliver material may be limited by the capacity of the hotend to melt it. For that reason some nozzles may not make sense for you, depending on what hotend you are using.

5. Consider the 3D printer’s kinematic capacity.

What is the top speed your printer can handle within your own quality parameters?
And what are your build speed requirements?

To maximize the build speed a calculation needs to be made to determine what are the nozzle sizes that can deliver the desired output just below the top speed threshold.

As an example, and using a simplification not dependent on geometry, 
if a part has a volume of 500 cm^3, 
and you want to print it in around 4 hours,
knowing your printer can print properly at speeds up to 200mm/s, 
you need a 35 mm^3/s average Volumetric Flow Rate. (500 000 mm^3 / 14400 s)
Let's say your hotend can deal with so much flow.
For this specific Volumetric Flow Rate 
and building using a 0.2mm layer thickness, 
a 0.6mm nozzle would need 314 mm/s print speed average.
Outside the printers kinematic capacity.
a 1.2mm nozzle would need 151 mm/s print speed average.
Inside the printers kinematic capacity.

All values presented above are subject to approximation

For some applications there are nozzle sizes that have throughputs outside of your printer’s capacity to deliver good parts at a specific build speed. Those will be useless.

What Nozzle Material To Choose?

The 3 most common materials that correspond effectively to distinct end use applications, are:

• Brass – Thermal Conductivity of ~111 W/m @20C K
• Copper – Thermal Conductivity of ~383 W/m K @327C
• Hard metals
  • Stainless Steel – Thermal Conductivity of ~14 W/m K @20C
  • Hardened Steel – Thermal Conductivity of ~31 W/m K @20C
  • Tungsten– Thermal Conductivity of ~139 W/m K @327C
• and Hybrid.

Brass

Brass is mostly used when the application requires low temperature – below 300C – and non abrasive material.
It is a soft metal sensitive to mechanical and chemical threats. To improve its features it is usual to coat this metal with a harder material like Nickel.

Bondtech applies a Nickel coating to some of our Brass nozzles to provide protection against corrosion, erosion, and abrasion. Nickel coated nozzles have more corrosion resistance and lower coefficient of friction, which allows slicker feeding of material and delays plastic adhesion to the nozzle’s surface.

Copper

Copper is mostly used when the application requires high temperature and non abrasive material.
Because Copper is sensitive to oxidation, Copper nozzles are also usually delivered with a specific technical coating to improve its superficial properties.

For instance Slice Engineering delivers their Bridgemaster nozzles with a super tough, carbide based surface coating that reduces wear from abrasive filaments.

Hard Metals

Hard metals are used when abrasive materials are required at any processing temperature requirement.

Abrasive materials include composites made of thermoplastics and (carbon or glass) fibers or made of a thermoplastic binder filled with metal powder.

The downside of using hard metal nozles is, with the exception of Tungsten, they are limited in their capacity of quickly conducting heat from the hot block to the material. This feature makes them react slow and require overshooting the temperature to improve results.

Hybrid

To work with abrasive materials there is another type of nozzles. The hybrids.

Hybrid nozzles are made of more than one material to exploit each material’s advantages and minimize their downfalls. For instance a Brass nozzle with a ruby tip can have a good thermal performance, be used to print with abrasive materials and have a relative extended life.
Ruby, Sapphire or Diamond tips can be used.

What Nozzles are compatible with my printer?

The nozzle thread and length is an important constraint on nozzle compatibility. If the heat block on your 3D printer isn’t compatible with the thread on the nozzle, it will not fit or, even if it seems to fit, it can cause catastrophic failure. Get to know the features of your hotend well before buying a nozzle.

Be aware the nozzle neck length is very important and it must bridge the gap towards the heat break. If it’s too short and it doesn’t flush perfectly with the heat break’s bottom, it will fail.

The 3 most common thread standards are:

• RepRap
• MK8
• MK10

There are also several proprietary thread standards. We mention just a few here:

• Creality Pro – used on CR-10S Pro, CR-10S Pro V2 and CR-10 Max.
• Raise3D Pro – used on the Pro2, Pro3 and E2 series.

Find thread standards and compatible models inside each tab. Click each arrow to expand.

Should I Use Standard or CHT?

Purchase Bondtech nozzles here