Flanged Nuts Serrated ZINC PLATED STEEL Hex M3 M4 M5 M6 M8 M10 M12 DIN6923 Serrations displace material and create a locking feature which is resistant to vibration. The protruding flange increases the bearing surface of the nut allowing it to be used with irregular and oversized holes.

Threads are metric coarse(most common);

M4 x 0.70mm Pitch M5 x 0.80mm Pitch M6 x 1.0mm Pitch M8 x 1.25mm Pitch M10 x 1.50mm Pitch M12 x 1.75mm Pitch M16 x 2.00mm Pitch M20 x 2.50mm Pitch