UKPOC forums

Hey guys,

Maybe a dumb question but I thought it best to confirm here. The bolts with "10" and "8" on their heads represent 10.9 and 8.8 tensile strength respectively right? Its odd they just have a single number as the internet has no trace of them.

Thanks,

Yep that’s right
Use 8.8 bolts on our steelwork in telecom.
I’ll take a few Photos of the heads today

Kit

I’m not sure that those numbers do represent the tensile strength on our cars. I’m familiar with the grading of bolts and the numbering but on these cars I’ve only ever seen the numbers corresponding to the thread size so M6 threads have 6 on the head, M8 has 8 and M10 has 10.

If anyone has seen different numbers then of course it proves the theory wrong.

I think the reason for doing this is for easy identification in the factory.

Going off at a tangent slightly My MX-6 is Japanese built as are all the old bikes I ever owned and I worked for a Japanese machine builder. The reason why the bolts have a ‘non-standard’ head size I.e. M8 bolts with either a 12 or 14mm AF head is so that they are torqued correctly at build. They use torque wrenches and torque spanners preset for the head size. So M8 bolts that don’t need to be so tight when In aluminium are 12 and places like the brakes they have 14. This might be a better way to judge which are higher tensile bolts.

Please do tell me if I’m wrong then I won’t embarrass myself again somewhere else.