A stud bolt is a mechanical un-headed fastener with a fully or partially threaded body that, with additional hardware, can secure two adjacent objects or surfaces. Unlike many types of bolts, this particular style is not driven into an object or surface, but passed completely through. Nuts or flanges on either end of the bolt then hold the two objects firmly together.
The ability to adjust the tightness is a key element lending to the popularity of the stud bolt in a variety of applications. Engineering, motor, automotive, petrochemical and nuclear industries all make use of these bolts which can be specially contoured to distribute stress evenly, reducing the occurrence of breakages. Internal combustion engine cylinders, inspection covers, tank lids, car wheels and even domestic gate latches use this simple but effective design. While the dual ended nature of the stud bolt is one of its greatest assets, it can also be use as an anchor bolt in civil and architectural engineering.
This is accomplished through cast-in-place techniques that insert one end of the rod into setting concrete. The threaded end provides added resistance to pullout and machinery or other objects may be fastened to the exposed threading with a single nut or flange. The materials used for stud bolts and corresponding nuts and flanges depend largely on the use, though steel alloys are the industry standard. Zinc and cadmium plating are common finishes that enhance the corrosion and environmental resistance of steel.
The manufacturing process used to create stud bolts is similar to that of other bolt types. A steel wire rod is first heated consistently for an extended period of time and all rust particles are removed. If needed, the metal is coated for added protection. Cold forging is then used to shape the rod at room temperature and the rod is forced through dyes at high pressures to be shaped into long perfectly round rods. Once cut down to the desired length, cold forging is again used to implement high pressure rollers which press in the thread pattern.
In stud bolts, threading is either pressed along the entire rod, or on equal portions of each end, leaving a smooth center segment. The finished bolt is then ready for use in a variety of applications. A pilot hole is made in each of the objects or surfaces to be joined and the rod is inserted. A nut or flange is then tightened on each end to create the desired clamping force. A wrench, spanner or pliers may be used when tightening must be high and precise. Stud bolts with a smooth center fragment should be considered carefully.
If a tight fit is desired than this portion must have a width the same or smaller than the combined width of the articles to be fastened. Alternatively, a wider segment allows the surfaces to “float,” providing a degree of give. It is important to consider the materials to be fastened as well as the strength and corrosion resistance required of the bolt materials. Other considerations include the bolt length and diameter.