Screws SAE 1020 material, zinc plated, with the following dimensions: 6x40 and 6x60 = 14 tonnes / month 6x80 and 6x100 = 4 tonnes / month 8x60; 8x80; 8x100 and 8x120 = 6 tonnes / month 10x80; 10x100 and10x120 = 6 tonnes / month in according to the drawings attached