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Originators and Designers of Specialty Reamers and Cutting Tools Since 1918

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Reamer Sizing Calculator

Reamer Sizing Calculator

Use this tool to quickly find the correct reamer size for your application. Simply enter the nominal and maximum hole diameters, and the tool will calculate the hole tolerance, recommended maximum and minimum reamer diameters, and the resulting manufacturing tolerance. These values help guide reamer selection and ensure the finished hole meets your dimensional requirements.


Hole Tolerance = Max hole – Nominal
Max Reamer Diameter = Max Hole – 0.15 × Tolerance
Min Reamer Diameter = Max Reamer – 0.35 × Tolerance
Manufacturing Tolerance = Max Reamer – Min Reamer


Hole Tolerance: ... in
Maximum Reamer Diameter: ... in
Minimum Reamer Diameter: ... in
Manufacturing Tolerance: ... in