There’s a specific moment of frustration every installer knows: the stainless steel screw is almost seated, then suddenly it won't turn. The driver stalls, the hex head strips, or—worst case—the shank snaps. This isn't bad luck or bad technique; it's galling. Also called cold welding, it's the number one cause of installation failure with stainless fasteners. Understanding why it happens is the first step to preventing it, saving time, money, and wasted materials on your project.