A J-bolt is a type of fastener characterized by its J-shaped bend on one end, which resembles the letter "J." This shape allows the J-bolt to be embedded into concrete or other materials with the curved end protruding, creating an anchor point for attaching objects, such as beams, posts or other structural components.

J-bolts are commonly used in construction and engineering projects where items need to be securely fastened to concrete or masonry surfaces. They are often used for attaching structural supports, columns, beams, machinery and equipment.