Nut, Screws, Washers and Bolts?

[Brockett]

No not that old joke but a query about specification and supply
When I installed the engine bars on the Guzzi I had the feeling that the bolts and nuts supplied by GIVI were not really up to the job
The bars, supplied by Givi are installed at the fixing point where the down tubes and lower frame rails are bolted together with 30x10 mm Allen bolts with 8mm hex heads and these are torqued to 50 Nm onto "Stover" nuts.
The Givi bolts - are 50 x 10mm to allow for the spacers. The hex head is 6mm  and the nuts are "Nylock" style.
At 35Nm It felt as though the threads were galling or even begining to strip although this may have been the undersized hex head giving out. So I stopped at that.
I am thinking that if the frame bolts should be torqued to 50Nm then I should maybe buy some more robust bolts.
Any  thoughts on this?

[porter]

I fitted a set of Puig crash bars to a friends vstrom 1000 and the main through bolt snapped before the full torque was reached. So better bolts wouldn't go amiss if you're not happy.

[2112]

+1 for better bolts. The Guzzi Stelvio had a spate of crashes associated with Hepco & Becker crash bars where the bolts failed causing massive instability (similar frame design). Not nice and those stains won't polish out...

[Rusty Nuts]

  Horror story! Sounds as if you need M10x50 of the same tensile strength as the originals. It seems a bit remiss of Givi (and Hepco&Becker) to supply fastenings which would be fine for just the lugage system but not up to their dual function.

[kwackboy]

I've fitted a lot of Givi products and often I change the supplied nuts & bolts as they are in my opinion,  made of something that resembles cheese ... 

[pieman53]

I have just fitted a set of bars from Heed to my V Strom, this time it seems the bolts have been upgraded and were very well made. So, I proceeded to use these instead of replacing them.
Time will tell.

[Brockett]

The OE nut looks like stainless steel. The bolt looks zinc  plated (or something).
Is there a potential problem mixing nut and bolt materials?

[Robotstar5]

Industry standard for M10 cap heads is 8mm hex key, if you're going to replace them, look for 10.9 stamped on the head which indicates a higher tensile strength. BZP (bright zinc plate) finish should be fine, but if you're using S/S nuts and bolts make sure the threads are clean (use brush & brake cleaner) as they are prone to galling (sticking). It's probably worth using a decent fastener supplier such as gwr-fasteners, spalding, namric etc. instead of no-name Chineseum off Ebay.

[Dark-Strom]

There is galvanic corrosion between stainless and carbon steel (we use plastic shim between both at work.
Plated steel should be OK, as should through bolts of most materials.
I just wouldn't use a stainless bolt into a threaded steel hole etc.