metric comparison size · nominal diameter
12 mm
drill bit size.
A 12 mm bit measures 0.4724 in across (12.000 mm).
The metric diameter is the generated reference value; inches are a conversion. Commercial set contents vary.
Calibrated relative diameter · 1 in reference
12 mm · metric
0.4724 in
12.000 mm Designation12 mmmetric
Inch decimal0.4724nominal
Metric conversion12.000millimetres
Where this size sits from 0 to 1 inch 12 mm · 12.000 mm on a zero to 25.4 millimetre scale. Neighbor marks: 15/32, 11.9 mm.
Measured neighbors
What sits beside 12 mm.
“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.
A generated comparison series from 0.5 to 13.0 mm in 0.1 mm steps. It is not a claim that every size is included in every commercial set.
Open source record