number drill · nominal diameter
#53
drill bit size.
A #53 bit measures 0.0595 in across (1.511 mm).
The inch decimal is the published nominal designation; millimetres are a conversion.
Calibrated relative diameter · 1 in reference
#53 · number
0.0595 in
1.511 mm Designation#53number
Inch decimal0.0595nominal
Metric conversion1.511millimetres
Where this size sits from 0 to 1 inch #53 · 1.511 mm on a zero to 25.4 millimetre scale. Neighbor marks: 1.5 mm, 1/16.
Measured neighbors
What sits beside #53.
“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