TA22 corona/mx62/ra60 front strut conversion. Disk bolt grade

[ToyTA22]

Hope you someone can help.

As above I am doing front strut conversion on my TA22 and found original, RT132 disk bolts only held by about 5mm into hub, there is no real markings on original bolt heads.
I put grade 8.8 hex bolts in and my brother, who is an aircraft engineer and built a couple of rally cars, freaked and said I should use at least a grade 10. Only problem is I can only buy internal hex bolts of that grade and I need hex head for pickup on rally trip meter.
I can't remember thread size and length at the moment i am not at my shed.

Any help would be appreciated.

[lexsmaz]

I guessing the bolt threaded diameter is at least 8mm & possibly 10mm, for proper bolt captivating / tensioned strength it needs to held in by at least the diameter of the thread, so in this case at least 8 or 10mm ( depending on bolt diameter ) or more, as your brother said i would be looking at a around a 10 grade too, if you go to good bolt place they should have Hex bolts to suit your needs or able to get some in ...

[RA35GT]

Have you tried a fastener shop?

You can get Class 10.9 hex head bolts.