I ordered the below from Graphskill...
M6 x 40 mm Hexagon Socket Button Head Screws A4 (T316) Marine Grade Stainless Steel
M6 Thin type nylon insert lock nut Nyloc Type. A4 stainless steel DIN985 | |
I asked the roof supplier for the washers and I think they sent me those and replacement bolts/nuts as well.
Hope you get your's sorted.