Tube 26×34 for extruder and injection where

I’v been searching for a week now and I can’t find the tube for the extruder and injection machine….
I know someone sells them at the pp-bazar, but I want to find it cheaper.

Does anyone have tips?

It’s nearly impossible to find in my experience. I am in the US so all of the metric parts have proven difficult. (stupid imperial system).

There is 35/25/5mm hollo bar that seems readily available and there is an extrusion screw being sold on the bazar that is designed for this narrower ID, but I am not sure about standard fittings with the 35mm OD yet.

hola, ya buscaste tubo de acero negro?

se me ocurre que quizá tengas que hacerle ranuras y meter anillos tipo pistón de moto o de podadora, para que tengas cero o ningún claro y no pierdas material.

Otra que se me ocurre es que te ayudes de un tornero.


please help me!

Hello, I did the test, and I have a problem with the fuel transfer because the tube and plunger have 1 mm difference the plastic is filtered inside the tube 🙁 any solution?

it´s seamless, so in order to be perfectly compatible with other components, so you won´t have to change anything the tube must be 34 mm outer diameter and 26 mm inner diameter? Thanks for the answer 🙂

2mm wall will be strong enough to withstand the pressure, but you won’t be able to thread the end with the 1″ BSP  thread, you will have to use a very fine pitch thread instead and will need a custom nozzle/fittings.

Is the tube seamless on the inside or is it welded?

The thickness of the tube has to be 4 mm? I can get 2 mm thick tube with inner diameter 26 mm for 5 euro. Thanks for the answer.

@fade-roymarkinez you’re welcome
@andyn exactly

I’d agree with @xxxolivierxxx about 0.5-1mm overall clearance is a good balance, the screw will still generate enough pressure. If it’s too tight and the screw rubs the metal can gall and the screw and barrel can cold-weld together. If this happens you won’t get them apart again with out destroying something.

@xxxolivierxxx Thanks for the info!
This helps me a lot

@sonik Yes and no. 1mm (0.5mm each side) to 2 mm (1mm each side) of clearance is good enough, if your drill bit is tighter it will cause grinding of the inside of the tube when the metal expands/contracts due to heating

@xxxolivierxxx I don’t understand that: “ensure that the drill bit you get has a diameter of at least 1 or 2mm less than the internal diameter of the tube.”
Isnt it supposed to fit as tight as possible?

@fade-roymarkinez I would advice you not to stick to the same Precious Plastic measurements so strictly, just find any tube with close measurements and ensure that the drill bit you get has a diameter of at least 1 or 2mm less than the internal diameter of the tube. As a suggestion, look for places that sell “piston tubes”, since those are perfectly smooth on the inside

Hey @fade-roymarkinez, it is indeed tricky to find this tube, especially for an affordable price.
I bought a 6m tube 35×4,5mm (so inside ø26) and cut it in 530mm-pieces. As we needed only two of them, we are selling the rest now – 25€/piece.
Will put it on the Bazar as well, but feel free to contact me anyway 🙂