M8-1.0 Din 439 Class 04 Hex Jam Nut Zinc (Pack Qty 2,500) BC-M8FD439B by Shorpioen

Class 04 metric hex jam nuts are tightened against the work surface and a Style 1 or Style 2 hex nut is tightened against the jam nut to keep it from loosening. Class 50 A2 stainless hex jam nuts are used in the same manner with A2 stainless screws | Class 04 hex jam nuts shall be made of a steel that conforms to the following chemical composition-- Carbon: 0.58% maximum; Manganese: 0.25% minimum; Phosphorus: 0.060% maximum; Sulfur: o.150% maximum. Class A2 stainless steel | HV 188 - 302 (Rockwell B88 - C30)