Found 2 products about

double washers sems screw

Yuhuang black nickel plated sems screw with spring washer and flat washer

Yuhuang black nickel plated sems screw with spring washer and flat washer

Available in any combination of screw type, head style, washer and thread configuration.
M2 M2.5 M3 steel with balck round pan phillips flange washer head machine screw

M2 M2.5 M3 steel with balck round pan phillips flange washer head machine screw

To meet the need , there are holes in the rod, which can prevent the bolt from loosening when subjected to vibration.