Screws When people choose screws, they usually look at size, thread pitch, and head type first.But in real applications, what truly determines whether a screw will fail is often the material. Rust, stripped threads, breakage, deformation, or loosening over time—many of these issues are not caused by poor machining, but by choosing the wrong material from the start. --- 1. Why Does Screw Material Matter So Much? In use, a screw typically faces multiple factors at the same time