M40 x 1.5mm Fine Pitch Castle Nuts (DIN 935-1) - Steel Gr.6 Self Colour Castle Nuts are commonly used within the automotive industry and, when staked with a pin, may be utilised as a locking nut. The crenels on the crown of this nut both give it its name and provide a space for the cotter\/split pin to be inserted through. Once Castle Nuts have been secured with a pin, they become locked in place and resistant to tightening or loosening. As a result, Castle Nuts are also reusable unlike some other locking nuts. These Fine Pitch Castle Nuts are made from Gr.6 High Tensile Steel and have a black self colour finish. For larger quantities or custom lengths, please email and one of our team will provide you with a quotation. M40 x 1.5mm Fine Pitch Castle Nuts (DIN 935-1) - Steel Gr.6 Self Colour