This self-locking hex nut with a nylon insert is made of steel and finished with a Zinc Flake coating. It's manufactured to DIN 985 and ISO 10511 standards and rated at strength class 10. The non-metallic insert provides the locking action, and the nut features metric threading. The Zinc Flake coating combines zinc and aluminum to deliver superior corrosion resistance compared to a pure zinc layer of the same thickness. Please note: class |10| nuts are rated per DIN 267-4 and have a lower load capacity than class 10 nuts rated to ISO 898-2. Mechanical overloading may cause the threads on either the nut or bolt to strip.