number drill · nominal diameter
#42
drill bit size.
A #42 bit measures 0.0935 in across (2.375 mm).
The inch decimal is the published nominal designation; millimetres are a conversion.
Calibrated relative diameter · 1 in reference
#42 · number
0.0935 in
2.375 mm Designation#42number
Inch decimal0.0935nominal
Metric conversion2.375millimetres
Where this size sits from 0 to 1 inch #42 · 2.375 mm on a zero to 25.4 millimetre scale. Neighbor marks: 3/32, 2.4 mm.
Measured neighbors
What sits beside #42.
“Nearest” means nominal diameter only. It does not make a neighboring size acceptable for a tolerance, tapping, reaming, or fastener application.
Source record
ASME.
The standard text is paywalled. Number and letter series are cross-checked against public manufacturer charts; exact standard edition/page verification remains a release gate.
Open source record