For the 3d printer RepRap Prusa there are several rails (smooth rods) that guide the printer head on the different axises. The printer head uses several linear bearings to glide along the rails.

There isn't any specification on what kind of material would be best suited for this purpose with the linear bearings. My first assumption would be for stainless steel because it won't corrode (rust) on the surface, but I'm not sure if this is true for all printers (whether they are 3D printers or not) as a different material may allow the linear bearings to glide more easily. Aluminum would have been my second choice but I have the same reservations of which grade would be least resistant.

This resource has some limited information but does not help with which would be best suited for this particular application.

What material is best suited for this purpose?

  • 2
    $\begingroup$ Since Reprap was mentioned, I hope people don't mind me plugging our Digital Fabrication proposal. $\endgroup$
    – Mark Booth
    Oct 26, 2012 at 17:16

3 Answers 3


For ball bearings, you almost always want to use the hardest, smoothest material you can find. Stainless steel would do nicely. Aluminium will be far too soft, and will simply be worn down the the steel ball bearings.

Plastic bearings like these Drylin from Igus can use aluminium rails:

Igus DryLin


Well, I got proper industrial linear bearings recently, along with stainless steel rails.

The properties of interest is that the material is smooth and hard to minimise friction. In fact, the stainless steel rails I obtained was both hardened and polished.

Aluminium could be dented by stainless steel bearings affecting performance.

Having said this, for a printer, which has very little weight/force, materials of differing hardness is probably fine. If you just want to reduce friction, just get polished material, or else polish it yourself (although stainless steel would probably maintain smoothness better since it is harder).

  • $\begingroup$ Is there a specific grade of stainless steel? $\endgroup$
    – DogEatDog
    Oct 26, 2012 at 2:49

You do not want to use stainless steel with linear bearings because that type of steel is not hard enough and the bearing will wear grooves into the rod. You want high carbon steel with hardness greater than HRC 60.


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