number drill · nominal diameter

#13
drill bit size.

A #13 bit measures 0.1850 in across (4.699 mm).

The inch decimal is the published nominal designation; millimetres are a conversion.

Diameter conversion cross-checked

Calibrated relative diameter · 1 in reference

#13 · number

0.1850 in

4.699 mm

Designation#13number

Inch decimal0.1850nominal

Metric conversion4.699millimetres

Where this size sits from 0 to 1 inch

#13 · 4.699 mm on a zero to 25.4 millimetre scale. Neighbor marks: 4.7 mm, 3/16.

0 25.4 mm

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Measured neighbors

What sits beside #13.

“Nearest” means nominal diameter only. It does not make a neighboring size acceptable for a tolerance, tapping, reaming, or fastener application.

Other naming systemsABSOLUTE DIAMETER DELTA

4.7 mmmetric 0.1850 inΔ +0.001 mm 3/16fractional 0.1875 inΔ +0.063 mm 4.6 mmmetric 0.1811 inΔ -0.099 mm 4.8 mmmetric 0.1890 inΔ +0.101 mm

Same seriesNEAREST NOMINAL ROWS

#14number 4.623 mmΔ -0.076 mm #12number 4.801 mmΔ +0.102 mm

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

#13drill bit size.

What sits beside #13.

ASME.

#13
drill bit size.