Types of fits

details on the three types of fits

1. Types of Fits

2. What are fits? Fit is defined as the degree of freedom of tightness between the mating parts in an assembly . Fit obtaining parts are either movable joint or fixed joint .

3. Clearance fit This means there is a gap between the two mating parts . Clearance fit is arises at the Diameter of the shaft is smaller then the hole . The minimum diameter of hole is grater then large diameter of the shaft . Clearance value is positive when in this type of fit.

4. Clearance fit

5. Clearance fit Maximum Clearance: It is the difference between the maximum size of hole and minimum size of shaft . Minimum clearance : It is the difference  between the maximum size of shaft and minimum size of the hole.

6. Clearance fit The  most commonly used fits of the clearance type are. Slide fit Easy Slide Running Fit Slack running Fits Loose Running Fits

7. Transition fit Transition fit is neither loose nor tight as like clearance fit and interference fit . The transition fit is two types they are. Wringing Fit Push fit

8. transition fit

9. Transition fit Wringing fit:  It is provides either zero interference or clearance . Wringing fit is used where parts can be replaced with out difficulty during minor repairs. Example of Wringing fit :gears of machine tools . Push fit : The push fit is characterized by it is clearance . It is used for parts , that must be dissembled for during operations of a machine Example of push fit : gear slip bushing.

10. Interference fit There is no gap between the faces and there will be an intersecting of material will occur . The interference type of fit the minimum allowable diameter of the shaft is larger then the maximum permissible diameter of the hole as the diameter of the shaft is larger then the diameter of hole.

11. Interference fit

12. Interference fit The hole and shaft are intended to be attached permanently The interference fits are classified into 3 types they are. Force fit Tight fit Heavy Force and shrink fit

13. Interference fit Force fit: This type of fits are employed for mating parts. This are not disassembled during their service life. Example of force fit: Gears on the shafts of a concrete mixer , Forging machine . Tight fit: This type of fits are provide less amount of interference than force fits. Tight fits are employed for mating parts , which are maybe replaced while overhauling the machine Examples of Tight fit: Stepped pulleys on the drive shaft of a conveyors , cylindrical grinding machine .

14. Interference fit Heavy Force and shrink fit: Heavy force and shrink fit type of fit there is negative allowances. For assembling the parts here more force is required.