Galling

NOT a material defect! NOT caused by corrosion! NOT a common phenomenon, but it can happen. With austenitic screws the thread can seize as if welded, already during the first tightening. What causes galling, and which methods reliably prevent it?

Galling of stainless and acid-resistant screws is not caused by a material defect, but by mechanical irregularities and/or failure to follow the assembly technology. You can find out here, point by point, what that technology is: handle the screws carefully, and avoid every possibility of mechanical damage to them.

With NONOX stainless steel screw joints, galling of rough surfaces can still cause problems even today. It is not uncommon for the phenomenon to be assumed to be caused by corrosion; in contrast, other triggering causes usually lie in the background, such as coarse thread machining or other surface damage.