Difference between control limits & tolerance limits in statistical quality control (SQC)?

Question

what is the difference between quality control and tolerance limits in sqc?

Answer 1

mean (+ and - ) 3 sigma contains 997 out of 1000 in a normal distribution.

so depending upon how stringent you want your testing to be, you can set tolerance limits less(strict) or more (lax) than 3 sigma.

Answer 2

d