This self-locking hex nut with a nylon insert is made of steel and features a zinc flake coating (Cr(VI)-free) in accordance with ISO 10683 flZnnc. The nut is standardized to DIN 985 and ISO 10511 and includes a non-metallic locking element. It comes with a metric thread. The zinc flake coating is a blend of zinc and aluminum and poses no risk of hydrogen embrittlement. Please note: Class |6| nuts have a strength rating per DIN 267-4 and offer a lower load capacity than a Class 6 nut per ISO 898-2. Mechanical overloading may cause the threads of the nut or bolt to strip.