DIN 439 Hex Nut A2-035 Low

Material stainless steel A2. Property class A2-035. Metric thread pitch. Nut height diameter x 0.5. Special nuts are nuts whose design, use, dimensions, or other characteristics differ from a standard hex nut.
Examples include low nuts (thin nuts), flange nuts, castle nuts, rivet nuts, square nuts, diamond nuts (diamond-shaped profile), sheet metal nuts, and welding nuts.
Materials include steel, plain or zinc-plated (bright zinc, Zn, zinc), stainless steel (A2), and acid-resistant steel (A4).
How to choose the right nut? The rule is that the nut’s hardness, material, and coating should be at least the same as those of the fastener used (bolt, screw).