Dear SJ Hi Generally the spec and limits should be same digits. eg If the spec is 10 then limits should be 9.5 to 10.4 eg If the spec is 10.0 then limits should be 9.95 to 10.04 eg If the spec is 10.00 then limits should be 9.995 to 10.004 If the limit is 10.0000 Then the desired limits be 9.99995 to 10.00004 I hope the concept of rounding of rules also to be considered