Bar Sag = .006
AA Dimension = 6
AB Dimension = 14
AC Dimension = 32
Solution: You may notice that the SM and MM TIRs are different from the given. This is because
bar sag must be accounted for. In this example, .006 inch must be added to the MM TIR, and .006
inch must be subtracted from the SM TIR for correct calculations, which makes the SM TIR+.024
inch and the MM TIR .
020 inch.
Figure 46 shows the calculation using the cross dial alignment form. When using this form, you
may find it convenient to use mils instead of thousandths of an inch. This allows the use of whole
numbers and avoids confusing decimals. For example, if the TIR was .027 inch, you would enter 27
on the form. When using mils, remember the solution will also be in mils; that is,+32.5 would
actually be+.0325 inch. The example in Figure 46 uses mils and the same given data as above.