Originally Posted by Don Dalton
Dave you are right,it's just a number.The designer determines where you should be tolerance wise w/n that number.
Years ago at IBM they tried to set an example to the world .Go with the Metric System it's simpler to use.We did double tolerancing to try and sell the idea.Result- Lots of training and money wasted.Most of the Tool Makers and Machinist hated it. I don't know what system is being used in Industry,but with all the work (jobs) going off shore (primeraly China) the system of choice I think would be Metric.