Wednesday, May 2, 2012

Nozzle Orifice Diameters

On the RepRap IRC, tonight, the subject of nozzle orifice diameters came up.  For the J-Head hot-end, I have always used a slightly smaller drill bit in order to drill the nozzle orifice.  This is because a drill bit usually drills a slightly larger hole than it's rated size.

Since this subject came up, and I have a small collection of other hot-ends, I decided to use a set of pin gauges and measure the nozzle orifice to see what the size really is.  Since my pin gauges are in SAE, the closest I can get is to one thousandth of an inch.  In order to measure them, I started with a pin gauge that was a little smaller than the hole and incrementally worked my way up through the pin gauges until I found one that didn't fit.  So, the size that I have listed is the last size that actually fit the hole.  It is entirely possible that the orifice is slightly bigger than that which is listed; but, it is certainly smaller than the next size pin gauge.  So, these measurements are giving the hot-end orifice the "benefit of the doubt", so to speak.

All hot-ends listed were purchased with a 0.50mm orifice specified.

  • Budaschnozzle (Lulzbot)....0.021
  • J-Head Mk IV-B (Reifsnyder Precision Works)....0.019
  • MakerBot Mk V (MakerBot)....0.019
  • MakerGear (MakerGear)....0.019
  • ParCan 2 (ParCan)....0.019

The metric to SAE conversion is as follows:

  • 0.01969    0.50mm
  • 0.02008    0.51mm
  • 0.02047    0.52mm
  • 0.02087    0.53mm
  • 0.02126    0.54mm
  • 0.02165    0.55mm
  • 0.02205    0.56mm

Please note that the listed hot-ends may be from other companies and/or individuals and they are in no way related to and/or endorsed these measurements.


  1. Do you have a way to measure the length of this final nozzle section, I would be interested in knowing it's length and then also the diameter of the extruded filament (die swell) these different nozzles give with the same material and temperature applied and used in them.

  2. RichRap,

    Please see the latest blog entry as I have measure the orifice length of some popular hot-ends.