Frequently Asked Questions    How To Install    Choosing Your Tubing    Measuring Your Filament

How to Choose Your Fittings

Fittings tend to wear out and loose teeth, so its never a bad idea to swap in new ones when you change your Bowden tube.

What are the differences between them?

First, the size of the tubing it accepts. Bowden tubes for 1.75mm filament are 4mm outer diameter. Part numbers beginning with PC4 indicate "Push Connector 4mm"

The next difference is threading. Most Bowden systems use either an M6 ("Metric 6mm"), M5, or M10 thread. 01 Threading is also common, which is a 1/8 inch thread. The distance between the threads is called the pitch.

Which fitting is right for me?

The easiest way it to look closely at the pictures, paying close attention to the measurements. We are working to build a list of printers for each fitting size, but it isn't complete yet. Please help us out by emailing or tweeting at us, and let us know what printer you're running, and what fittings it uses.

3D Printers and HotendsFitting (Size-Thread)


This is our most popular fitting, used by the Creality CR-10, and many of the newer RepRap printers. We also carry a PC4-M6C, which is a more compact, lightweight version.


This is the Compact version of the PC4-M6


This is another common size for RepRaps, and is utilized in the Monstah Adaptor for the popular HE280 hotend.


This is used in some of E3D's hot ends.


This fitting has an 1/8 inch thread .

What if I accidently purchase the wrong fittings?

Please contact and we will provide instructions to return the un-used fittings for an exchange or refund.

What if you don't carry the fitting I need?

We are constantly expanding our selection to meet the needs of the community. Please tweet us @CapTubes or email with your printer or hotend, and the specs of the fittings you need.

Frequently Asked Questions    How To Install    Choosing Your Tubing    Measuring Your Filament