fractional-inch drill · nominal diameter
33/64
drill bit size.
A 33/64 bit measures 0.5156 in across (13.097 mm).
The fractional diameter is exact; decimal and metric values are conversions.
Calibrated relative diameter · 1 in reference
33/64 · fractional
0.5156 in
13.097 mm Designation33/64fractional
Inch decimal0.5156nominal
Metric conversion13.097millimetres
Where this size sits from 0 to 1 inch 33/64 · 13.097 mm on a zero to 25.4 millimetre scale. Neighbor marks: 13 mm, 12.9 mm.
Measured neighbors
What sits beside 33/64.
“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