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GATE 2019 ME (ME1) – Question 46

Metrology and Inspection · Limits, fits and tolerances · 2 marks · Multiple choice

A turned shaft diameter is $65.00^{+0.01}_{-0.05}$ mm. It receives 50 μm TiN coating with allowed variation ±5 μm. Find minimum hole diameter (mm) just providing clearance fit.

  1. 65.01
  2. 65.12
  3. 64.95
  4. 65.10

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Correct answer: (B) 65.12

Explanation

Maximum shaft diameter is 65.01 mm. Maximum coating thickness is $55\ \mu\mathrm m=0.055$ mm on each side. Hence the limiting clearance-hole diameter is $65.01+2(0.055)=\mathbf{65.12}$ mm. **B**.