1. Limits and fits

2. in practice, no component can be　manufactured to an exact size
deciding the upper and lower limits of size
For example, a dimension of 10 ± 0.02
 a part will be acceptable if manufactured anywhere between the limits of size of 9.98 mm and mm.

4. ISO limits and fits
methods of dimensioning a hole

8. Bases of fits system of limits and fits : the hole basis,
the basic diameter of the hole is constant while the shaft size varies according to the type of fit.
The shaft can be accurately produced to size by turning and grinding.
Generally it is usual to recommend hole-base fits

9. (b) the shaft basis.
the hole size is varied
A series of drills and reamers is required for this system, therefore it tends to be costly.

10. Selected ISO fits hole basis
selected hole tolerances: H7 H8 H9 H11;
selected shaft tolerances: c11 d10 e9 f7 g6 h6 k6 n6 p6 s6.

11. Boxed dimensions