Wheel Bolt Thread Engagement Worries

[NaweedM]

Hi all, a year ago I got 15mm spacers done for the rears at a wheel shop where they also fitted longer bolts to compensate for the standard length. This weekend i decided to do the front spacers myself and get some bolts based on the "39mm" bolts they installed on the rear. Upon removing both front and rear wheels, i notice a difference in how deep the bolts go inside. Did they spec the wrong bolts for the rears? i counted the amount of turns i can do with the rear bolts and its 5 turns by hand. 5 and 1/4th if I really give it some force with my hands.

Is this still within acceptable limits and I'm unnecessarily worrying that i drove like this for a year or should i actually get this sorted out?

My fronts will soon have the 5 turns thread engagement as i bought the bolts based on the rear bolt spec.

 

[Zedebee]

In very simple terms, the wheel bolts should be longer than standard by the same number of millimetres as the spacer is wide. This assumes that the spacer has properly seated on the wheel hub flange.

 

[NaweedM]

This is what I was thinking as well, since I got it done at a specialised wheel shop. Was wondering if they installed the wrong type or knew this is still safe

 

[brillomaster]

They really look undersized to me. But If the wheels stayed on a year I doubt there's any damage, though I would get the right length set on there. About £50 I'd have thought off ebay.

Edit to add... standard rule of thumb is minimum engagement is the witdh of the bolt. So an m12 should engage at least 12mm... m14 should engage at least 14mm and so on.