Question

‘GO’ and ‘NO GO’ snap gauges are to be designed for a shaft \( 36.000^{+0.070} \, +0.010 \) mm. Gauge tolerance can be taken as 5% of the hole tolerance. Following the ISO system of gauge design, the respective sizes of ‘GO’ and ‘NO GO’ gauges are

• A. 36.013 mm and 36.067 mm
• B. 36.015 mm and 36.065 mm
• C. 36.018 mm and 36.062 mm
• D. 36.020 mm and 36.060 mm

Hint:

The ‘GO’ gauge checks the maximum allowable size, while the ‘NO GO’ gauge ensures that the part does not exceed the tolerance.

Answer 1

The Correct Option is A

In the ISO system of gauge design: - The ‘GO’ gauge is designed to ensure that the hole is at the maximum size, while the ‘NO GO’ gauge ensures that the hole is not larger than the maximum allowable tolerance.
Given:
- The nominal size of the shaft is \(36.000\) mm.
- The tolerance is \(+0.070\) mm (upper limit) and \(+0.010\) mm (lower limit).
- Gauge tolerance is 5% of the hole tolerance.
The total tolerance on the shaft is \( 0.070 + 0.010 = 0.080 \) mm. The gauge tolerance is 5% of this, so: \[ \text{Gauge tolerance} = 0.080 \times 0.05 = 0.004 \, \text{mm}. \] - The ‘GO’ gauge size is:
\[ 36.000 + 0.070 - 0.004 = 36.013 \, \text{mm}. \] - The ‘NO GO’ gauge size is:
\[ 36.000 + 0.070 + 0.004 = 36.067 \, \text{mm}. \] Thus, the correct sizes for the ‘GO’ and ‘NO GO’ gauges are 36.013 mm and 36.067 mm, respectively. Therefore, the correct answer is (A).