"S S" screws most commonly refers to screws made from stainless steel, which are valued for their superior corrosion resistance, strength, durability, and aesthetic appeal. Composed of an iron and chromium alloy, stainless steel creates a passive oxide layer that prevents rust, making these screws ideal for wet environments, outdoor use, and high-temperature applications. Stainless steel screws come in various grades (like 304 or 316) and types (such as wood, machine, or self-tapping) to suit different materials and projects.