Studs are type of mechanical fasteners used in fastening various products, including pipes used in different applications. These type of fasteners are threaded on one or both ends. Studs are headless bolts, threaded , sometimes with different threads. One end of the stud is secured to an object while the other end is used typically with a nut. They are available in both Metric and English threads. Stud Fasteners are available in all forms to suit any application.
- Metallic studs
- Silicon bronze
- Titanium etc.
- Non-metallic studs
- Fiber-reinforced plastic
- Polyvinyl chloride (PVC)
- Polyvinylidene fluoride (PVDF)
- Polytetrafluoroethylene (PTFE)
- Synthetic rubber
Finishes on studs:
Studs are available in various finishes. Some popular finishes are:
- Can be anodized
- Coated with phosphate or black oxide
- Plated with gold, silver, tin, nickel, zinc
- Zinc chromate
- Chrome galvanized etc.
- Good strength
- Reasonable cold ductility
- Excellent high temperature ductility
- Good conductivity
- Excellent corrosion resistance
- Good bearing properties
- Low magnetic permeability
- Gland or tap-end stud: It has an interference fit at one end and a free-running thread at the other.
- Double-end stud: It has free-running threads at both ends.
- Three-bolt stud: Used in high-temperature/pressure applications.
- Standard stud: Used for general-purpose applications.
- Studs help in eliminating deviations from perfect squareness in an assembly.
- The basic advantage of using a stud rather than a bolt or screw is the ability of a nut to “float” and adjust on the nut end threads.
- The thicker the cover plate, or the longer the tapped hole, the more important the stud becomes.
- In assembling and reassembling heavy parts , for example, turbine casings and cylinder heads, studs can act as pilots.
- In the automatic assembly of small, lightweight units, studs help in reducing assembly costs. They permit quick and easy “stack up” of gaskets or other different parts of a joint or two different pipes.
- Studs also help in reducing the need for the large hole clearance and close hole alignment which are usually required by a cap screw or bolt.
- Studs with an interference-fit thread or proprietary-lock thread on the tap or pipe end gives a positive lock against turning and loosening.
- Studs also provide sealant to prevent leakage of fluids through holes tapped in porous materials.