2. Corrosion Resistance Many manufacturers provide M20 bolts with coatings or treatments (like galvanization) to enhance corrosion resistance. This is vital for outdoor and industrial applications where exposure to moisture and chemicals is common.

4. Strong Load-Bearing Capacity Made from high-quality steel and coated with zinc, these screws are designed to handle significant loads without compromising stability. This makes them suitable for heavy-duty applications where strength is paramount.

Black phosphate drywall screws are specialized fasteners designed specifically for the installation of drywall and related materials. They are characterized by a unique black phosphate coating that not only enhances their aesthetic appeal but also provides increased corrosion resistance. This coating is produced through a chemical process that creates a layer of iron phosphate on the screw's surface. This is crucial in construction environments where exposure to moisture and varying temperatures can lead to rust and degradation of standard screws.