I am not a mechanical engineer :) I feel much better with electronics, but I have a project in your domain now.

So, I have an aluminum housing, a steel bearing and an aluminum axis. I need to put them together. In my basement. They are designed to have the same diameter-30mm for the housing and 17mm for the bearing.

What preparations do I need? What equipment? What is the optimal method?

This is the bearing I am going to use :


  • $\begingroup$ please add a link to the bearing datasheet to your post $\endgroup$
    – jsotola
    Commented Sep 6, 2021 at 2:21
  • 1
    $\begingroup$ I suggest that while specifying installation methods for bearings is squarely within the realm of engineering, actually doing the installation is best left to craftspersons such as a millwright. Engineers with tools leads to trouble! $\endgroup$
    – Tiger Guy
    Commented Sep 6, 2021 at 18:51
  • $\begingroup$ I have to install the first few units... $\endgroup$ Commented Sep 6, 2021 at 20:35
  • 1
    $\begingroup$ Not as professional as NMech's answer, but a vice, or better yet an arbor press should work. $\endgroup$
    – Drew
    Commented Sep 7, 2021 at 2:47
  • $\begingroup$ Thank you! I was thinking, how to keep the bearing vertical through? $\endgroup$ Commented Sep 7, 2021 at 3:49

1 Answer 1


Installing bearings is much easier than removing them.


The main thing is that you keep Bearings and surfaces Clean. Make sure that you don't get the bearing into contact with contaminant, and clean the surfaces before installation.

The another important thing - it might seem obvious - its to double check the dimensions of the bearing and the hole (fits and clearances). Usually, the bearing manufacturer has a pretty detailed manual with shaft tolerances depending on many factors (e.g. shaft diameter, type and magnitude of load etc).

Finally, the most important thing is handle bearings with care. If they fall on the floor, or have even relatively minor impacts, then the ball (or other rolling elements) can develop dents which will a) reduce the life of the bearing, b) make the bearing underperform.

installation methods

There are a few installation methods. Sometimes all its need is the hand pressure (some even go as far as saying that, if you can't fit a bearing with the pressure of your hand you are doing something wrong).

The next step is mallet with a Bearing Fitting Tool

enter image description here figure 1: SKF Bearing Fitting Tool Kit Hammer, TMFT 36-H (source indiamart)

Then there is the hot mounting method (this is usually for medium sized bearings. Essentially what happens is that you heat the bearing in order to increase its size and then you slide in the shaft. That has the effect that the bearing is then essentially pressfitted on the shaft

enter image description here figure: SKF bearing heaters (source Wychbearings)

The final option is probably hydraulic mounting (although this is for much larger bearings).

  • $\begingroup$ Thank you! I am in a small trouble here, I don't understand the clearance requirements. It says P6, P5, whatever it means. Mind having a look? $\endgroup$ Commented Sep 6, 2021 at 1:24
  • $\begingroup$ skf.com/ca/en/products/rolling-bearings/roller-bearings/… $\endgroup$ Commented Sep 6, 2021 at 1:24
  • $\begingroup$ P6 and P5 (or less) its a class categorization specific to SKF - at least to my knowledge. Basically Normal has wider tolerances, P6 smaller, P5 even smaller and SKF boasts that it can do smaller than P5 which collectively calls superbearings. SKF has a mount/dismount link which usually describes the procedure. However keep in mind, that the tolerances are significantly affected by loading conditions. $\endgroup$
    – NMech
    Commented Sep 6, 2021 at 1:37
  • $\begingroup$ Can I use some generic fitting tool, or should it be by the same vendor that I take bearings from? $\endgroup$ Commented Sep 6, 2021 at 1:59
  • $\begingroup$ So the load should be roughly 200kg, axially and radially. Not sure about torsion. $\endgroup$ Commented Sep 6, 2021 at 3:02

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