Difference Between Welded Joint and Riveted Joint

Joining is a part and parcel in manufacturing to assemble two or more components. Such joining can be made either permanently or temporarily. Although permanent joint does not allow disassembly of parts without rupturing them, it has immense demand in assembly as it can provide a strong, leak-proof and inherently anti-loose joint. Welded joint and riveted joint are two commonly used permanent joining processes; however, now-a-days riveted joints are mostly superseded by various advanced welding processes.

By definition, welding joint is one type of manufacturing process where two or more materials can be joined permanently by coalescence formation with or without the application of external heat, pressure and filler material. On the other hand, riveted joint is also one type of permanent joining process where two or more components can be assembled together by means of small cylindrical rods (called rivets) inserted into pre-drilled holes. Similarities and differences between welded joint and riveted joint are discussed in the following sections.

Similarities between welded joint and riveted joint

  • Both welding and riveting are mechanical joining processes. No chemical reaction occurs during joining.
  • Both are permanent joints.
  • Both can be applied for joining of two or more components together.
  • Both can provide sufficiently strong and sound joint.

Differences between welded joint and riveted joint

Welded Joint Riveted Joint
No hole is required to drill on the parent components for joining them by welding. Riveted joints require pre-drilled holes on the parent components for the passage of rivets.
Load carrying capacity of the parent components before and after welding remains more or less same. Due to drilled holes on the parent components, cross-sectional area reduces and thus load carrying capacity also reduces.
Many welding processes (fusion welding mainly) tend to change metallurgical properties of the base plate surrounding the weld bead. Metallurgical properties of the base plate remain unaltered in rivet joining.
Strength of the welded joint is very high; often it is more than the strength of base plates. Strength of riveted joint is comparatively low.
Welded assemblies are prone to fail under vibration. Riveted joints remain strong enough under vibrations.
Welded joints are usually leak proof. Riveted joints are not completely leak proof.
Welded joints require no additional plates or straps, except filler material in some cases. Riveted joints require additional cover plates, straps as well as multiple rivets for joining purpose.
Welded assemblies are lighter. Due to use of additional parts, riveted assemblies become heavy.
Designing welded assembly is easy, cheap and time efficient. Designing riveted assembly requires a large volume of calculation, thus it is time consuming.
Time required for welding is also less. Drilling holes, inserting rivets and then pressing them—all take substantial amount of time.
Appearance of welded assemblies is good. The reinforcement from the weld bead can be removed easily to improve appearance. Rivet heads always remain protruded from the surface, which hampers the appearance of riveted assemblies.
Various shapes such as circular or elliptical shafts can be easily joined by welding. Such shapes cannot be joined by riveting without using extra plates.
Welding can be applied for joining of metals as well as ceramic, plastic and also composites. Riveting is useful only for joining of metals.
Welded joints have a wide variety of applications where a permanent joining is desired. Examples include, but not limited to, pipe or rod joining, sheets or plates joining, automobile industries, joining of railway tracks, common household applications, etc. Although now-a-days riveted joints are almost superseded by welded joints, these were used in:

  • Pressure vessels
  • Gas cylinders
  • Boilers
  • Bridges
  • Ship tussles
  • Various frames

 

References

  • Book: Design of Machine Elements by V. B. Bhandari (Tata McGraw Hill Education Private Limited). Buy this book
  • Book: Analysis and Design of Machine Elements by V. K. Jadon and S. Verma (I. K. International Publishing House Private Limited). Buy this book
  • Book: Fundamentals of Machine Drawing by S. Singh and P. L. Sah (PHI Learning Private Limited). Buy this book