Hot Dip Galvanised Mild Steel. Washers are Form A type (standard, thick, most common). Lets bring things together.
HOT GALVANISED FLAT FORM A WASHERS MILD STEEL TO FIT BOLTS SCREWS BS4320F
FORM A WASHERS FLAT SOLID BRASS DIN 125A M2 M2.5 M3 M4 M5 M6 M8 M10 M12 M16
A4 MARINE GRADE STAINLESS STEEL FORM A WASHERS THICK WASHER TO FIT BOLTS SCREWS
Form A Washers Flat Solid Brass DIN 125A M2-M16 for Hardware