Every fit falls into one of three categories based on the interaction between the hole and shaft tolerance zones.
: Rotating shafts, sliding parts, or items that need easy hand-assembly. Fit Tolerance
: The shaft is always smaller than the hole, ensuring a gap for movement. Every fit falls into one of three categories
: The shaft is always larger than the hole, requiring force or thermal expansion/contraction for assembly. ) to define fits.
: H7/g6 (precision sliding), H11/c11 (loose agricultural machinery).
The ISO 286 Standard uses an alphanumeric code (e.g., ) to define fits.