Where can I get a new one?
These nozzles have been tested over the past few years with a variety of abrasive filaments. They are a lot cheaper than high-tech ruby nozzles, so they are prefered by many users.
These hardened steel nozzles were made to be used with abrasive filaments.
They do not have a good thermal conductivity, so you will be probably forced to print with a higher temperature – usually + 10°C.
You can use this nozzle for almost all filaments.
But I would advise you to use a different nozzle type for standard PLA, ABS, PETG materials, such as one of these:
Dimensions and nozzle types
This is a standard nozzle for V5, V6, Mosquito, NF-Crazy hot ends.
It is suitable for almost every 3D printer, such as i3 Mega, Kossel, Prusa and so on…
These nozzles are usually made with these inner diameteres:
0.15, 0.20, 0.30, 0.40, 0.50, 0.60, 0.80, 1.00, 1.20 mm
Standard nozzle diameter is 0.4 mm.
The smallest usable nozzle diameter is a 0.20 mm type. You can print smaller details with a better quality.
When choosing the nozzle, please do not forget that the filament flow grows exponentially with the nozzle diameter – S = pi * (d*d)/4.
This means that your printing time will increase or decrease exponentially if you change the nozzle to another diameter from the standard 0.4 mm type.
These hardened steel nozzles do not have a good thermal conductivity which results in lower temperature inside the nozzle.
You will be forced to print with a higher temperature, cca + 10°C against the standard brass nozzle.
Thermistors measure temperature inside the hot end, not in the nozzle.
The nozzle is pernamently being cooled down with a flowing filament and the inner surface of the nozzle will always be smaller than the temperature of the hot end.
If you have ever wondered what a hot end “hot tightening” means, have a look at a thermal expansion coefficient in the table above.
Most of the known materials are known to expand their dimensions while heating up.
In our case V6 nozzle should theoretically expend (get longer in Y dimension) after heating up from a room temperature of 20°C to 240°C (PETG for example) to:
12.5 * (240-20)*8*0.000001 = 0.022 mm.
Heat break expands too, but not so much due to the lower temperature and lower thermal expansion coefficient.
It is always better to re-tighten the nozzle after heating up to the printing temperature, but usually thermal expansion takes care of that.