The carriage bolts carriage bolts by size into half round head carriage bolts (corresponding standard GB / T14 and DIN693), small head carriage bolts (corresponding standard GB / T12-85). Carriage bolts, consisting of the head and screw (with male cylinder) of a class of two-part fastener is required with the nut for fastening two parts with a hole. Carriage bolts refers head square neck screws, carriage bolt 2 Basic English for general information, bolts used to connect two objects, usually through the pupil, needs and nut (nut) with the use of a single role can not afford to connect. Tools generally with a wrench. Mostly hexagonal head first class, generally larger. Carriage bolts applied to the tank, the Quartet neck in the process of installing the card in the slot, can be prevented from rotating bolt, carriage bolts can be moved in parallel in the tank. Because of the rounded head carriage bolts, not designed hexagonal cross slot available within the class or power tools in the actual connection process can also play a security role. Materials: carbon steel, Q235,45 # steel, stainless steel nominal diameter: 5mm - 20mm Length: 15mm - 300mm Surface treatment: zinc, chromium, copper, stainless steel surface blackening 3 standard head square neck bolts ( carriage bolts) specification: German standard DIN603 stainless steel small head square neck carriage bolt specification: GB GB / T12-85 large stainless steel head square neck carriage bolt specification: GB GB / T14-8