Question

A hole is specified as ${70}_{+0.12}^{+0.00}$ and shaft ${70}_{-0.10}^{-0.22}$ is to be produced on a machine which has process capability of 0.4mm. To produce the components with more than 99% of acceptability it is decided to use selective assembly. The no. of groups to which the holes and shafts can be divided to ensure that the assembly conditions are same or better than original assembly is

• A. 4
• B. 7
• C. 3
• D. 6

Answer 1

The correct option is A 4

Selective assembly : Process capability of hole and shaft are equal but more than the desired tolerance. So, the holes and shafts can be divided in 4 no. of groups.