Galvanised set screws are ideally used when passed through a threaded hole in the outer object and tightened against the inner object to prevent it from moving relative to the outer object. It exerts clamping force through the bottom tip that projects through the hole. Grade 10.9 High tensile hexagon head set screws DIN 933 are sometimes referred to as a fully threaded bolts or set pins. They are easily identified by their 10.9 head markings and usually but not always have metric thread forms. The most common surface finish in use is Cr3 bright zinc plated. Hot dipped galvanised finishes are becoming ever more popular, particularly in the rail industry sector.