fractional-inch drill · nominal diameter
3/8
drill bit size.
A 3/8 bit measures 0.3750 in across (9.525 mm).
The fractional diameter is exact; decimal and metric values are conversions.
Calibrated relative diameter · 1 in reference
3/8 · fractional
0.3750 in
9.525 mm Designation3/8fractional
Inch decimal0.3750nominal
Metric conversion9.525millimetres
Where this size sits from 0 to 1 inch 3/8 · 9.525 mm on a zero to 25.4 millimetre scale. Neighbor marks: 9.5 mm, V.
Measured neighbors
What sits beside 3/8.
“Nearest” means nominal diameter only. It does not make a neighboring size acceptable for a tolerance, tapping, reaming, or fastener application.
This row is at the exposed edge of its series.
Source record
Drill Bit Size Chart.
Fractional sizes are exact rational multiples of one inch.
Open source record