2.1.1 Tolerance
Types of Tolerances
Unilateral Tolerance-provides an allowable variation in only ONE direction, the part can either be smaller or larger not both Bilateral Tolerance-the part is allowed to be larger or smaller than the specified dimension Limit Dimensions-provides an upper limit and a lower limit for the dimension, that means there are no plus or minus signs in this type of tolerance Calculating Tolerance Find the distance between the smallest the part is allowed to be and the largest the part is allowed to be. The smaller a tolerance is, the more exact it must be made. This is expensive, so you don't want to be more exact (or have a smaller tolerance) then you actually need. The larger a tolerance is, the less perfect it must be made. This allowed the part to be made cheaper and faster. |
Defining Fit
Clearance Fit-a space always results when mating parts are assembled. In other words, when the parts are put together there is some wiggle room.
Interference Fit-two parts are held together by friction. In other words, when you put the parts together it is such a tight fit, that they don't need glue to be held together.
Transition Fit-two mating parts sometimes have a clearance fit and sometime have an interference fit. In other words, sometimes there is wiggle room and sometimes it is a tight fit.
Clearance Fit-a space always results when mating parts are assembled. In other words, when the parts are put together there is some wiggle room.
Interference Fit-two parts are held together by friction. In other words, when you put the parts together it is such a tight fit, that they don't need glue to be held together.
Transition Fit-two mating parts sometimes have a clearance fit and sometime have an interference fit. In other words, sometimes there is wiggle room and sometimes it is a tight fit.
2.1.2 Connecting Components
Connection Presentations |