M12-1.75 Serrated Hex Flange Nut/Metric Class 8 Steel/Plain Finish (Quantity: 100 pcs)

The bearing surface of the flange has serrations which displace material on the mating surface when the nut is wrenched into place, forming a connection which resists loosening. | Flange provides a more uniform bearing stress to clamp force ratio than other lock nuts