Fixing Solar PV Panels requires specialised fasteners which includes Stainless Steel nuts & bolts
We have them.
M8x30mm Hex Head Set Screw
M8x50mm Hex Head Set Screw
M8x30mm Button Head Screw A2
M8x50mm Button Head A2
M8x16mm Flat Washer
M8x20mm Flat Washer
M8 Split Washer A2
M8 Nylocs A2