number drill · nominal diameter

#10
drill bit size.

A #10 bit measures 0.1935 in across (4.915 mm).

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

Diameter conversion cross-checked

Calibrated relative diameter · 1 in reference

#10 · number

0.1935 in

4.915 mm

Designation#10number

Inch decimal0.1935nominal

Metric conversion4.915millimetres

Where this size sits from 0 to 1 inch

#10 · 4.915 mm on a zero to 25.4 millimetre scale. Neighbor marks: 4.9 mm, #9.

0 25.4 mm

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Measured neighbors

What sits beside #10.

“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

4.9 mmmetric 0.1929 inΔ -0.015 mm 5 mmmetric 0.1969 inΔ +0.085 mm 4.8 mmmetric 0.1890 inΔ -0.115 mm 3/16fractional 0.1875 inΔ -0.152 mm

Same seriesNEAREST NOMINAL ROWS

#9number 4.978 mmΔ +0.063 mm #11number 4.851 mmΔ -0.064 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

#10drill bit size.

What sits beside #10.

ASME.

#10
drill bit size.