Suggested conduit wall thickness

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1

Hello,

planning a 60 x 40 x 10 cm MPCNC right now. Will be used for milling aluminium mostly. What conduit (25 mm) wall thickness should be used here best?

I was thinking of 2 mm pipes, but I read somewhere on the forums this could be too much weight. On the other hand, 1.2 mm is cheaper too, so there’s two advantages of 1.2 mm wall thickness over 2 mm. Does the finishing (polished or not) matter?

1.) sanded finish steel, 25 x 2 mm (most expensive) http://www.metall-kunststoffhandel.de/produkt/edelstahl-rundrohr-025x20-mm-geschliffen-k320/
2.) chrome finish steel, 25 x 1.2 mm (moderate priced) https://www.heimwerkertools.com/schrankaustattung/schrankrohre-schrankrohrlager/schrankrohr-rund/haefele-schrankrohr-stahl-schwarz-gebuerstet-eckig
3.) non-smoothed steel (rough outside), 25 x 2 mm (cheap) http://www.ebay.de/itm/Stahlrohr-Konstruktionsrohr-Rundrohr-Stahl-Rohr-von-10-0-bis-139-7mm-/272262888875

edit: found a long thread on these forums, I tend to 2.) because it’s lighter and easier to cut by myself.

2

The best thing to do is go try it out. Usually it is very obvious which one is best. The numbers do not tell you everything. If you were to pick up all three of these the longest common length and just hold one end in your hand and the other on the ground you should see very quickly which one sags less under its own weight.

This was a huge subject in the beginning. I’m not saying the sag test is best but it can tell you a lot. Surface finish is sometimes important. No one here can tell you what’s best. Around here the hardware stores seem to get different brands of conduit from month to month, So I am always looking for something better. Regular EMT conduit has always been by far the best option for the money, with SS being second but costing about 10x as much. Nothing else has even come close.