The strength grade of carriage bolts is selected according to the working pressure. The performance grades of carbon steel carriage bolts are 3.6, 4.6 and 4.8. The standard can refer to GB3098.1, while the material of stainless steel carriage bolts is mainly austenitic stainless steel, which owns good heat resistance, good corrosion resistance and good weldability.

Carriage bolts are divided into large semi-circular head carriage bolts (corresponding to standard GB/T14 and DIN603) and small semi-circular head carriage bolts (corresponding to standard GB/T12-85) according to head size.

Carriage bolts can also be called square neck bolts. They consist of a square neck under a round head, so they are also called square neck bolts. The carriage bolt is composed of head and threaded screw. It needs using in conjunction with nut to fasten and connect two parts with through holes. Another feature of the carriage bolt is that its threaded rod is a cylinder with an external thread.

A carriage bolt consists of mushroom head and screw (with external threads), it needs matching with nut to fasten and connect two parts with through holes. One of the widely used carriage bolts is standard DIN603 with metric M5 to M20 thread.