A light duty nut used in applications where regular tightening and removal is done by hand. Plated...A light duty nut used in applications where regular tightening and removal is done by hand. Plated in Trivalent Chromium (Cr3) Zinc. Standard metric thread. Thread Dia. mm: M12 Socket Size mm: N/A Height mm: 21.0 Thread Type: Metric Finish: Zinc & Clear Cr3 Material: Carbon Steel.