Drill size center
Drill Size Charts and Conversions
Use one diameter basis to compare different drill naming systems, then keep nominal tool size separate from the hole your process actually produces.
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Drill reference
Drill Size Chart: Fractional, Number, Letter and Metric
Compare common drill designation systems using decimal inches and exact metric conversion methodology.
Read reference →Conversion referenceFractional, Decimal and Metric Drill Size Conversion
Convert fractional-inch drill sizes to decimal inches and millimeters using exact unit relationships and explicit display rounding.
Read reference →Lookup referenceNumber and Letter Drill Size Chart
Look up #80–#1 and A–Z drill designations by decimal-inch diameter and compare nearby alternatives.
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