Measuring Flashcards
Nominal size
Metric or imperial stander size for the purpose of general identification
Actual size
actual measured size or dimension
Basic size
theoretical size that tolerances are applied. Can apply to both mating parts
Limit of size
Can be largest (upper limit ) size and the smallest (lower Limit) size a part can still be acceptable
MMC Maximum metal condition
This will be the smallest hole and largest shaft .Least material removed
Least metal condition
Largest hole smallest shaft most material removed
Tolerance
total amount of variation permitted in duplicate parts
unilateral tolerance
one direction
Bi lateral tolerance
In both directions (equally or unequally )
limit dimensions
only the maximum and minimum dimensions of a part is is specified
Allowance
intentional difference between two mating parts at mmc
positive allowance
the hole is larger than the shaft ( negative is hole smaller )
three types of fit
interference fit
clearance fit
transition fit
interference fit
negative allowance and the total tolerance do not exceed the allowance
clearance fit
have a positive allowance
