number drill · nominal diameter

#24
drill bit size.

A #24 bit measures 0.1520 in across (3.861 mm).

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

Diameter conversion cross-checked

Calibrated relative diameter · 1 in reference

#24 · number

0.1520 in

3.861 mm

Designation#24number

Inch decimal0.1520nominal

Metric conversion3.861millimetres

Where this size sits from 0 to 1 inch

#24 · 3.861 mm on a zero to 25.4 millimetre scale. Neighbor marks: 3.9 mm, #23.

0 25.4 mm

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Measured neighbors

What sits beside #24.

“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

3.9 mmmetric 0.1535 inΔ +0.039 mm 3.8 mmmetric 0.1496 inΔ -0.061 mm 5/32fractional 0.1563 inΔ +0.108 mm 4 mmmetric 0.1575 inΔ +0.139 mm

Same seriesNEAREST NOMINAL ROWS

#23number 3.912 mmΔ +0.051 mm #25number 3.797 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

#24drill bit size.

What sits beside #24.

ASME.

#24
drill bit size.