What does limit fit tolerance mean?
Two extreme permissible sizes of a part between which the actual size is contained are called limits. The relationship existing between two parts which are to be assembled with respect to the difference on their sizes before assembly is called a fit. Tolerance is defined as the total permissible variation of a size.
What is limit measurement?
Limits of Size: The term limits of size referred to the two extreme permissible sizes for a dimension of a part, between which the actual size should lie. The largest permissible size for a dimension is called upper or high or maximum limit, whereas the smallest size is called lower or minimum limit.
Why are limits and fits used?
Limits and Fits are used to define tolerances for mating parts. Limits are most commonly used for cylindrical holes and shafts, but they can be used for any parts that fit together regardless of the geometry. A limit is the upper and lower tolerance for a shaft or hole. A fit consists of a pair of limits.
What is fit explain types of fit?
The three types of fit are: Clearance: The hole is larger than the shaft, enabling the two parts to slide and / or rotate when assembled, e.g., piston & valves. Location / transition: The hole is fractionally smaller than the shaft and mild force is required to assemble / disassemble e.g., Shaft key.
Why are limits and fits important?
Limits and Fits are used to define tolerances for mating parts. Limits are most commonly used for cylindrical holes and shafts, but they can be used for any parts that fit together regardless of the geometry. A limit is the upper and lower tolerance for a shaft or hole.
How are fit and tolerance related?
‘The extreme permissible values of a dimension are known as limits. The degree of tightness or looseness between two mating parts that are intended to act together is known as the fit of the parts. Tolerance on the other hand is the total amount that a specific dimension is permitted to vary.