Studs explained here are metal rods that are threaded at both the ends. In circumstances where metal parts or metal components become impossible to be fixed with bolts or screws, these metal studs come into play and help in fitting them securely at the desired locations. In this process, the stud is screwed through one of the metal parts and allowed to enter midway across the preceding metal part; the entire system is then secured by tightening a nut over the outer top terminating end of the stud (see fig).
Studs are usually made up of high tensile steel, with sizes of 2 BA, ¼" BSF, 5/16" BSF and 3/2" BSF.
Studs may be classified with the following main types:
Standard Studs: These are in the form of plain rods having threads cut over their two ends.
Waisted Studs: As the figure illustrates, in this type of studs the central unthreaded section is kept clean and the diameter equal to the core of the threaded portion. This arrangement helps to keep the stud simple and lighter in weight. The two ends are appropriately threaded for the required clamping operations.
Stepped Studs: Here, one of the threaded end sections of the stud has larger diameter than the opposite threaded portion. The larger threaded section is generally used for fixing metal parts made up of softer material thereby allowing greater area of the material to be gripped, confirming reliable fixation.
These studs can also be employed for replacing broken studs, where normally the hole needs to be re-tapped making the hole size bigger and suitable for screwing with the broader threaded ends of stepped studs.
Shouldered Studs: Referring to the fig. we find one of the threaded end collars of the stud having an integral machined shoulder terminating from the plain mid section of the stud body. The collared disc seats itself firmly over metal parts making the screwed assembly clamped more rigidly compared to other types of studs discussed above.