passenger seat bolts

97 300tdi. I removed the rear seats for the boot floor replacement, but have mislaid the bolts... Anyone know the correct size and do they need to High Tensile or something special?

I drilled the threads out and slid some M6 HT bolts in with nuts and washers on. Broke a few of the original ones when I removed my interior for cleaning.

Thanks Matthew - will follow your advice today and finally finish this project !
that is until start on the sills...

Oooooo funny that. I've got a set of sills and rear wheel arches to be getting on with but I really can't be assed with it. Been under the disco this morning poking around but I can't find the motivation..... AND I need to take out a new rental on a welding cylinder (£150 quid filled). I need a kick up the jacksie