If nut shear stress equals half the bolt tensile stress, the required nut length should equal___________________?
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Answer: A. diameter of bolt
Explanation
Equal strength in fastening systems requires total shear resistance to match total tensile capacity. Nut threads experience shear stresses while bolt shanks experience tensile stresses under operational loads. Setting nut length equal to the bolt diameter balances shear and tensile strengths when shear stress is half tension. Fastener design equations balance the tensile area of the bolt against the shear area of internal nut threads. Nut height is traditionally proportioned as a ratio of the nominal bolt diameter to prevent thread stripping failures. Stress distribution across engaged threads is non-uniform, requiring empirical safety margins in threaded joint design.
A nut length of 0.75 times bolt diameter provides insufficient thread shear area for balanced joint strength. A length of 1.25 times bolt diameter exceeds the required minimum, adding unnecessary material weight to the fastener. A length of 1.5 times bolt diameter represents an overly conservative proportion when nut shear stress is half tension.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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