Heavy hex bolt have larger and thicker heads than regular or standard hex bolts, and are commonly used in a wide variety of applications. Heavy hex bolts are available in different sizes, both lengths and diameters, although all come with a hex head. Some types are threaded all the way up the shaft, while others have a smooth shoulder area. Heavy hex bolts are used in a variety of applications, including construction, steel fabrication, and automotive. They are often specified for high-pressure or high-temperature applications.