Bracing, bolts, and torque questions

[desmondo]

hi folks - I been messing around with the lower front brace on my 2003 facelift 2 and got myself in a bit of a pickle..... wondered if anyone has any insight into the following -

... the 17mm head M8 bolts that hold the brace to the chassis rails - I had it in my head that these should be torqued up to 55 ft-lbs, but having sheared the threads off 3 already I'm wondering if I have that wrong - anyone know the correct torque for the those? Maybe its 55 Nm?

... also, same deal with the bolts that hold the brace together, anyone know what torque they should be? Can't find that info anywhere and already stripped the threads off one...

.. and finally bolts in general - where do people source the correct spec bolts? I have a load of BZP bolts from screwfix stamped 8.8 on top that worked fine on my series 3 landy but 8.8 seems pretty low spec in terms of the torque it can handle. I looked online for 10.9 grade M8 bolts (which can supposedly handle 55 ft-lbs) but the only ones I could find were BMW ones and like £10 per bolt!! no thanks!


Thanks in advance for any insight!

[desmondo]

Uff just realised they're not M8, they're M10 - no wonder I couldn't find any online

[J03]

Most, if not all, M10 size bolts on these are 1.25 pitch    

55lb/ft should see you right with the chassis mounting, the same type bolts which mount the triangular strengthening plate use this spec. Maybe pull the cross bar bolts down to 45lb/ft.

[105e]

If suitable for application i use allen head bolts,  they all seem to come 12.9 as standard.. They are actually called cap head i think.

[desmondo]

Thanks guys, i have some of those cap head bolts, I think. Ta also for the pitch and torque advice. I'll give it another whirl...