Threads, Fasteners & Springs — Rivets are generally classified as permanent fasteners because they are installed by plastic deformation and are not intended to be removed without destruction.

Difficulty: Easy

Correct Answer: Incorrect

Explanation:


Introduction / Context:
Fasteners are often categorized as permanent or non-permanent. Riveting forms a mechanical joint by upsetting (deforming) the rivet shank, creating a clamped assembly that is not intended to be disassembled without drilling or destroying the rivet.


Given Data / Assumptions:

  • Rivets are set using force/heat to plastically deform the tail.
  • Service requires joint integrity over the life of the assembly.
  • Removal damages the rivet, unlike reusable threaded fasteners.


Concept / Approach:
Permanence stems from plastic deformation and lack of a reversible mechanism. This differs from screws/bolts, which can be unthreaded, and from welds, which are metallurgical bonds rather than mechanical fasteners.


Step-by-Step Solution:
1) Identify the joining method—upsetting a rivet vs threading.2) Assess removability without damage.3) Classify as permanent if removal requires destruction.4) Conclude the statement “not considered permanent” is incorrect.


Verification / Alternative check:
Maintenance manuals specify drilling out rivets for removal, confirming non-reusability and permanence.


Why Other Options Are Wrong:
Equating rivets with temporary threaded fasteners is false; welding is unrelated to rivet permanence; color does not determine classification.


Common Pitfalls:
Assuming blind rivets are reusable; misclassifying lock-bolts (hybrid systems) as threaded when they are also essentially permanent.


Final Answer:
Incorrect

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