Preferred fits and tolerance table for hole and shaft basis systems which are given in ISO 286-1 (2010) and ANSI B4.2-1978 standards. The usage of these tolerances is advised for economic reasons.
| ISO Symbol | Description | ||
| Hole Basis | Shaft Basis | ||
| Clearance Fits | H11/c11 | C11/h11 | Loose running fit for wide commercial tolerances or allowances on external members. |
| H9/d9 | D9/h9 | Free running fit not for use where accuracy is essential, but good for large temperature variations, high running speeds, or heavy journal pressures. | |
| H8/f7 | F8/h7 | Close running fit for running on accurate machines and for accurate location at moderate speeds and journal pressures. | |
| H7/g6 | G7/h6 | Sliding fit not intended to run freely, but to move and turn freely and locate accurately. | |
| H7/h6 | H7/h6 | Locational clearance fit provides snug fit for locating stationary parts; but can be freely assembled and disassembled. | |
| Transition Fits | H7/k6 | K7/h6 | Locational transition fit for accurate location, a compromise between clearance and interference. |
| H7/n6 | N7/h6 | Locational transition fit for more accurate location where greater interference is permissible. | |
| Interference Fits | H7/p6 | P7/h6 | Locational interference fit for parts requiring rigidity and alignment with prime accuracy of location but without special bore pressure requirements. |
| H7/s6 | S7/h6 | Medium drive fit for ordinary steel parts or shrink fits on light sections, the tightest fit usable with cast iron. | |
| H7/u6 | U7/h6 | Force fit suitable for parts which can be highly stressed or for shrink fits where the heavy pressing forces required are impractical. |
Preferred fits table (ANSI B4.2-1978)
| Basic Hole | Tolerance classes for shafts | |||||||||||||||||
| Clearance Fits | Transition Fits | Interference Fits | ||||||||||||||||
| H6 | g5 | h5 | js5 | k5 | m5 | n5 | p5 | |||||||||||
| H7 | f6 | g6 | h6 | js6 | k6 | m6 | n6 | p6 | r6 | s6 | t6 | u6 | x6 | |||||
| H8 | e7 | f7 | h7 | js7 | k7 | m7 | s7 | u7 | ||||||||||
| d8 | e8 | f8 | h8 | |||||||||||||||
| H9 | d8 | e8 | f8 | h8 | ||||||||||||||
| H10 | b9 | c9 | d9 | e9 | h9 | |||||||||||||
| H11 | b11 | c11 | d10 | h10 |
Preferable fits of the hole-basis system (ISO 286-1:2010)
| Basic Shaft | Tolerance classes for holes | |||||||||||||||||
| Clearance Fits | Transition Fits | Interference Fits | ||||||||||||||||
| h5 | G6 | H6 | JS6 | K6 | M6 | N6 | P6 | |||||||||||
| h6 | F7 | G7 | H7 | JS7 | K7 | M7 | N7 | P7 | R7 | S7 | T7 | U7 | X7 | |||||
| h7 | E8 | F8 | H8 | |||||||||||||||
| h8 | D9 | E9 | F9 | H9 | ||||||||||||||
| h9 | E8 | F8 | H8 | |||||||||||||||
| D9 | E9 | F9 | H9 | |||||||||||||||
| B11 | C10 | D10 | H10 |
Preferable fits of the shaft-basis system (ISO 286-1:2010)
Note: For economic reasons, the first choice for a fit should, whenever possible, be made from the tolerance classes shown with green color.
