This MF/MEF hex nut is made of plain steel, meaning it has no coating or surface treatment and offers virtually no corrosion resistance on its own. The nut is manufactured to DIN 934 standards and features a metric fine thread. Please note: Class |8| nuts are rated according to DIN 267-4 and have a lower load capacity than Class 8 nuts rated to ISO 898-2. Mechanical overloading can cause the threads on the nut or bolt to strip.