Subject: Machine Design -I

Topic: Machine Design consideration

Difficulty: High

Fit:

• Manufactured parts are required to mate with one another during assembly.
• When two parts are to be assembled, the relationship resulting from the difference between their sizes before assembly is called a fit.

Types of Fits:

a] Clearance fit

b] Transition fit

c] Interference fit.

Clearance fit (a) is a fit which always provides a positive clearance between the hole and the shaft over the entire range of tolerances.

Interference fit (b) is a fit which always provides a positive interference over the whole range of tolerances.

Transition fit (c) is a fit which may provide either a clearance or interference, depending upon the actual values of the individual tolerances of the mating components.