Hexagon blind rivet Material: steel galvanized for steel construction. M8 x 1,25 7'000 pieces M12 x 1,75 3'000 pieces Hexagon : M8 is 11 mm and M12 is 16 mm, tec. specs attached. Our design is already in production and can no longer change the hexagon. pneumatic/hydraulic setting tool, including spare parts delivery by the first week of October at the latest.