Other naming systemsABSOLUTE DIAMETER DELTA
fractional-inch drill · nominal diameter
5/8
drill bit size.
A 5/8 bit measures 0.6250 in across (15.875 mm).
The fractional diameter is exact; decimal and metric values are conversions.
Calibrated relative diameter · 1 in reference
5/8 · fractional
0.6250 in
15.875 mm Designation5/8fractional
Inch decimal0.6250nominal
Metric conversion15.875millimetres
Where this size sits from 0 to 1 inch 5/8 · 15.875 mm on a zero to 25.4 millimetre scale. Neighbor marks: 41/64, 39/64.
Measured neighbors
What sits beside 5/8.
“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