What is the use of the carriage bolt?

Generally speaking, bolts are used to connect two objects, usually through light holes, and they need to be used with nuts. A single can't connect. Tools generally use wrenches. The head is mostly hexagonal, usually larger. The carriage bolt is used in the slot. The square neck is stuck in the slot source during the installation process to prevent the bolt from rotating. The carriage bolt can move parallel in the slot. Because the head of the carriage bolt is round, there is no design of available power tools such as cross grooves or internal hexagons, which can also play an anti theft role in the actual connection process.
Material: Carbon steel, Q235, 45 # steel, stainless steel
Nominal diameter: 5mm--20mm
Length: 15mm--300mm
Surface treatment methods: zinc plating, chrome plating, copper plating, surface blackening.