Min thread diameter
The smallest diameter of polymer thread with which the pen can operate effectively; with a smaller thickness, the device will not be able to properly pass the material through the feeder. Usually, this diameter also corresponds to the regular thread diameter the device is designed for.
The most popular option for modern 3D pens is 1.75 mm; occasionally other values barely found — for example, some "heavyweight" high-performance models are designed for 3 mm threads.
Nozzle Diameter
The diameter of the nozzle provided in the pen.
The larger the nozzle, the thicker the lines produced by the pen will be (ceteris paribus; the actual thickness of the lines will also depend on the type of plastic and the adjusted temperature). In the thinnest models, the nozzle diameter is less than 0.5 mm, in the thickest models it is about 0.9 mm. Most modern 3D pens have nozzles in the range of 0.6 – 0.7 mm — this value is considered the most versatile and convenient for practical use.
Print Speed
The material feed rate provided by the pen. The higher this speed, the faster you can work with this model; on the other hand, the rapid supply of material requires increased accuracy and serious skills. The maximum value of this parameter in modern 3D pens is about 40 mm/s. Models with adjusted speed is also available (see below); for them, usually, the highest speed of operation is given in the specs.
