Wing grommets

[SCORPION]

After my wing split last year I decided to buy some grommets for the bolts.
They are only 3.9 Euros for 10 BUT the p&P was 9.9 Euros pushing the price up from 39 cents each to 138 cents. Total GBP £11.72. I didn't notice the P&P ripoff until I hit the complete transaction. I suggest if anyone is thinking of replacing grommets at the Technical meeting you do a bulk buy and share. Buy 30 at a time and it more than halves the cost.
I've just replaced 8 on the front wings and about half were badly distorted.

QUESTION: how tight do I screw the bolts down? Too tight and the wings may crack, can they be too loose ?

[Jet]

Can't imagine there is a torque value for wing nuts..but count me in Scorpion.

[sfh3l]

Good idea to replace all of these as they do get sad and tatty quite quickly. I am convinced that is what is leading to the spate of cracked panels around now. I thunk I have a very few of these, but i would be in for a bulk purchase, rather as Roger did with the SHC630 gearbox oil a few years ago.