Wheels adaptor bolt length

[Therealredford]

Hi. I have some 25mm 5x120 to 5x130 wheel adaptors to put porche wheels on my t6. I'm not sure how far the bolts supplied are supposed to engage in the hub due to the hub not being fully threaded from the mating face they only have about 9mm thread engagement max out of approx 25mm of thread in the front wheel hub. Is this right? Seems like the bolts should be longer?
To clarify this is to bolt the adaptor to the hub.

Image of original thread engagement vs hub bolt attached. Thanks

 

[jayc001]

Many of us run bolt on spacers so this should be the same thing. The picture is misleading as it's comparing apples with oranges. Bolt shoulder and seat type are very different but thread length looks similar.

As long as you get 7-8 full turns of thread engagement you'll be ok. I always put a blob of thread lock on my spacer bolts now as I've had them come loose.

 

[Therealredford]

Ok cheers. Yeah searching around it seems all adaptor bolts are all a similar length. I'm just surprised how little of the thread is engaged in the hub. It's about 7 threads. Wonder why they don't do the bolts slightly longer to engage with the full thread in the hub.