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ANSI/ASME B4.1 Limits & Fits Calculator (Inch Units)

This calculator implements ANSI/ASME B4.1 for inch-based non-threaded cylindrical parts. It supports RC (running/sliding), LC (locational clearance), LT (locational transition), LN (locational interference), and FN (force/shrink) fit classes.
Looking for ISO 286 metric fits (e.g., H7/h6)? Use the ISO 286 fits & tolerance calculator.

The calculated limits of size are the extreme values within which the actual size of the feature shall lie at the standard temperature of 20 °C (68 °F).

Calculator

Input parameters
Parameter Value Unit
Nominal size
Example: 9.85
 inch
Fit type
Fit detail
Note: Use a dot (.) as the decimal separator.

Results

Example output is shown below. Change inputs and click Calculate for your case.

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: Difference between maximum limiting size and nominal size.

Lower deviation: Difference between minimum limiting size and nominal size.

Tolerance: Difference between maximum and minimum size limits.

Clearance fit: Clearance exists under all tolerance conditions.

Interference fit: Interference exists under all tolerance conditions.

Transition fit: Either clearance or interference may occur depending on actual sizes.

Allowance: Minimum clearance (positive) or maximum interference (negative) at MMC.

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