Other naming systemsABSOLUTE DIAMETER DELTA
fractional-inch drill · nominal diameter
7/8
drill bit size.
A 7/8 bit measures 0.8750 in across (22.225 mm).
The fractional diameter is exact; decimal and metric values are conversions.
Calibrated relative diameter · 1 in reference
7/8 · fractional
0.8750 in
22.225 mm Designation7/8fractional
Inch decimal0.8750nominal
Metric conversion22.225millimetres
Where this size sits from 0 to 1 inch 7/8 · 22.225 mm on a zero to 25.4 millimetre scale. Neighbor marks: 55/64, 57/64.
Measured neighbors
What sits beside 7/8.
“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