The following data are given for calculating limits of

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The following data are given for calculating limits of dimension and tolerances for a hole: Tolerance unit i (microns) = 0.45 (D^1/3) + 0.001 D. The unit of D is mm. Diameter step is 18 – 30. If the fundamental deviation for hole H is zero and IT8 = 26i, the maximum and minimum limits of dimension for a 25H8 hole (in mm) are

1. 24.984 and 24.967
2. 25.017 and 24.984
3. 25.033 and 25.00
4. 25.00, 24.967

Correct Option: C

D = √18 &time; 30 = 23.24mm
i = 0.45³√D + 0.001D
= 0.45 ³√23.24 + 0.001 (23.24) = 1.307 mm
IT8 = 26i = 26 × 1.307 ≈ 33.98 34 m = 0.034mm
25H8 = 250.00 + 0.034mm.