Carriage bolts, also known as round head square neck screws, are fasteners with a special design that are widely used in situations where the bolt needs to be prevented from rotating. Its unique square neck can be stuck in the slot during installation, thereby preventing rotation while allowing the bolt to move parallel to the slot. The head of the carriage bolt is round, without a cross slot or hexagonal design, so it also has a certain anti-theft effect.

Common materials for carriage bolts: usually made of carbon steel (such as Q235, 35# steel, 45# steel) with performance grades ranging from 3.6 to 10.9, stainless steel (SS201, SS304, SS316) and other materials, with a tensile strength of 500MPA to 800MPA to adapt to different application environments and corrosion resistance requirements.

Surface treatment mainly includes galvanizing, chrome plating, copper plating, blackening and hot-dip galvanizing, etc., aiming to improve the corrosion resistance and appearance of the bolts.