Imperial Extruder and Injector Parts for USA

Hi all,

What is everybody using for tubes for the extrusion and injection machines here in the USA?

– is there extruded (seamless) tube that has standardized plumbing fittings compatible with the tube diameter?
– what size wood auger are you using inside the extrusion tube?
– what size rod are you using for the injection machine to fit in the injection tube? Or will we need to turn town some round stock to size?
– have you found an extrusion screw that will work for the inner diameter of extruded tubing available in the USA?

I have found the 34x26x4mm tubing to be impossible to find anywhere online.

There is 35x25x5mm tubing available and there is a maker Megatec.Center on the Bazar that has this size tubing and a matching extrusion screw for sale. However, I am left with the same question. Are there 35mm standard plumbing fittings that can be used with this size tube?

Thanks in advance,

Hello @dave2ndln
The specific tube requirements posted in the schematic files are indeed not easy to find outside of Europe. My suggestion is don’t sweat it, just find any tube you can with similar measurements. In both the injection and the extrusion machine, the only thing that matters is that the inner tube (injection) and auger bit (extrusion) fit as tight as possible inside the outer tube without jamming.

Something I found is that the best way to get seamless tube is to buy “Piston tube”, like those used for hydraulic machines.

For the injection machine, you can get a hollow tube, weld a small coin-like metal piece on one of the ends, and then smooth it with sanding paper, it will be much cheaper than buying round stock, but also harder to find the perfect size

@dave2ndln the extrusion screw you purchased will give you the best results indeed, please keep us posted on your build progress 🙂


Hi Oliver,
Thanks for your response, and for all of the knowledge you share on this forum.

There are some unfortunate drawbacks to the imperial measurement system. In fact I can’t think of any benefits.

The nominal tubing here in the US just doesn’t provide the right combinations for a tight enough fit with off the shelf parts for a tube/auger combination.

I decided the upgrade to an extrusion screw was worth it in the end and purchased a tube/screw combination on the bazar from

An unfortunate drawback to this solution is that we will have to machine the nozzle ourselves. Fortunately, we have the expertise in house.

Piston tubing looks real nice, and I suspect is priced accordingly.

Good tip on the injection machine. Thanks!