Under which classification of fits, does a driving fit fall?

Explanation:

Fit:

• It is the relationship that exists between two mating parts, a hole, and a shaft, with respect to their dimensional differences before assembly.

Types of fits:

• Clearance fit
• Interference Fit
• Transition fit

Interference Fit:

• In Interference Fit, the tolerance zone of the shaft goes above the tolerance zone of the hole.
• This means the shaft here is of large size, and the hole is of small size.

Types of Interference Fit:
There are three types of Interference fit:

• Force Fit
• Tight Fit
• Shrink Fit

Driving fits:

• It requires medium interference which can be assembled by higher forces for cold forging or hot forging.
• Driving fits are more reliable than tight fits.
• Example: Shafts, gears, bushes, etc.

Force fit:

• To mating the high interference fit, it requires a very high temperature for heating the part to assemble the shaft with a hole.
• The external force is required for the mating parts.
• Example: Gears, shafts, etc.

Tight Fit:

• It provides minimal interference than force fits.
• Example: Stepped pulley of a conveyor, cylindrical grinding of a machine, etc.