ANSI STANDARD LIMITS AND FITS CALCULATOR
ANSI standard limits and fits calculator was developed to calculate tolerances of inner and outer features of journal bearings, linear bearings, thrust bearings, bushings, ball bearings, roller bearings, housings, cylinder bores, drilled holes, linear and precision shafts, pistons, etc.
The calculator works in line with ANSI B4.11967 (R2004) standard which is based on inch units.
According to the input parameters of nominal size and
fit type selection among running and sliding [RC], locational clearance [LC],
locational transition [LT], locational interference [LN], force and shrink [FN]
fits, size limits for hole/shaft are calculated. The schematic representation of the fit is also drawn.
This calculator is applicable to nonthreaded cylindrical parts.
Limits of sizes that calculated are the
extreme values, within which the actual size of
the dimension shall lie, at the standard temperature of 20C or 68F.
Calculator:
Note : Use dot "." as decimal separator.
RESULTS 
HOLE 
Parameter 
Value 
Unit 
Hole Tolerance 


 
Hole Upper Deviation 


thou(0.001 inch) 
Hole Lower Deviation 


thou(0.001 inch) 
Maximum Hole Size 


inch 
Minimum Hole Size 


inch 
SHAFT 
Parameter 
Value 
Unit 
Shaft Tolerance 


 
Shaft Upper Deviation 


thou(0.001 inch) 
Shaft Lower Deviation 


thou(0.001 inch) 
Maximum Shaft Size 


inch 
Minimum Shaft Size 


inch 
FIT 
Parameter 
Value 
Unit 
Fit Type 


 
Maximum Clearance



thou(0.001 inch) 
Minimum Clearance



thou(0.001 inch) 
Definitions:
Nominal size: The size of a feature
of perfect form as defined by the technical drawing.
Deviation: The difference between a size and the corresponding nominal size.
Upper deviation: The difference between the maximum limiting size and the corresponding nominal size
of a feature.
Lower deviation: The
difference between the minimum limiting size and the corresponding nominal size
of a feature.
Tolerance: The difference
between the maximum and minimum size limits of a part.
Clearance Fit: A fit type where clearance exists between assembled parts under all tolerance conditions.
Interference Fit: A fit type where interference exists between assembled parts under all tolerance conditions.
Transition Fit: A fit type where clearance or interference can exist between assembled parts depending on tolerance conditions.
Hole Basis Fit System: A fit
system in which hole lower deviation is zero. In other words the lower limit of
size of hole is equal to nominal size. The required fit (clearance, interference
etc.) is obtained by keeping hole as defined and applying various tolerance
classes to shaft.
Allowance: The difference
between the maximum material limits of mating parts. Minimum clearance (+
allowance) or maximum interference ( allowance) between parts depending on the fit
type.
GD&T A means of dimensioning and tolerancing a part with respect to relationship and function of that part. GD&T is used to define how a part feature relates the other part features in the same part or in a mating part; it’s a way to dimension and tolerance with respect to part’s function, the way it works.
Supplements:

ANSI/ASME B4.1  1967 (R2004) Preferred Limits and Fits for Cylindrical Parts