Carriage Bolt

Carriage Bolts are a form of self-locking bolt that affords a level of security by using a flush-mount domed head, which permits access to remove or loosen these bolts from the nut side of the bolt only. Beneath the domed head of the carriage bolt is a square section that can be inserted into a corresponding square cut that is slotted in the material being joined so as to provide the self-locking feature that allows the bolt to be tightened from the nut side without a need to restrain the head with a wrench.