Final answer:
Tightening a capscrew or bolt beyond its torque value can lead to permanent stretching or breakage due to exceeding the tensile strength and causing plastic deformation that is irreversible.
Step-by-step explanation:
The correct answer is option b) permanent stretching or breakage. When a capscrew or bolt is tightened beyond its recommended torque value, it undergoes stress that can exceed its tensile strength.
This additional stress can lead to plastic deformation, where the metal is permanently stretched and will not return to its original shape once the force is removed.
If the stress continues to increase, it can ultimately cause the bolt to reach its fracture point, leading to breakage. The use of a wrench provides mechanical advantage, and adding a length of pipe increases leverage, predisposing to such over-tightening scenarios.
It's crucial to adhere to specified torque values to prevent compromising the structural integrity of the bolt or capscrew.
The correct answer is option (b) permanent stretching or breakage. When a capscrew or bolt is tightened beyond its torque value, it can cause permanent stretching or breakage of the material.
This is because the material experiences stresses beyond its elastic limit, leading to irreversible deformation. Ductile materials like metals gradually decrease in stress as strain increases, making them easier to deform.
However, when stress-strain values approach the breaking point, the material fractures.