M18x1.5 CASTLE NUT BL CL 8

Castle nuts look like crowns or turret of medieval castles. These nuts are used together with a bolt and a cotter pin to create a secure nut in place so that it cannot be tightened or loosened. In Imperial these are known as Slotted nuts.
Metric fine thread

GST Incl
Excl
M18x1.5 CASTLE NUT BL CL 8
NCAS18B15
Each
$5.7166