Other naming systemsABSOLUTE DIAMETER DELTA
fractional-inch drill · nominal diameter
41/64
drill bit size.
A 41/64 bit measures 0.6406 in across (16.272 mm).
The fractional diameter is exact; decimal and metric values are conversions.
Calibrated relative diameter · 1 in reference
41/64 · fractional
0.6406 in
16.272 mm Designation41/64fractional
Inch decimal0.6406nominal
Metric conversion16.272millimetres
Where this size sits from 0 to 1 inch 41/64 · 16.272 mm on a zero to 25.4 millimetre scale. Neighbor marks: 5/8, 21/32.
Measured neighbors
What sits beside 41/64.
“Nearest” means nominal diameter only. It does not make a neighboring size acceptable for a tolerance, tapping, reaming, or fastener application.
Source record
Drill Bit Size Chart.
Fractional sizes are exact rational multiples of one inch.
Open source record