number drill · nominal diameter

#57
drill bit size.

A #57 bit measures 0.0430 in across (1.092 mm).

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

Diameter conversion cross-checked

Calibrated relative diameter · 1 in reference

#57 · number

0.0430 in

1.092 mm

Designation#57number

Inch decimal0.0430nominal

Metric conversion1.092millimetres

Where this size sits from 0 to 1 inch

#57 · 1.092 mm on a zero to 25.4 millimetre scale. Neighbor marks: 1.1 mm, #58.

0 25.4 mm

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Measured neighbors

What sits beside #57.

“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

1.1 mmmetric 0.0433 inΔ +0.008 mm 1 mmmetric 0.0394 inΔ -0.092 mm 3/64fractional 0.0469 inΔ +0.098 mm

Same seriesNEAREST NOMINAL ROWS

#58number 1.067 mmΔ -0.025 mm #59number 1.041 mmΔ -0.051 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

#57drill bit size.

What sits beside #57.

ASME.

#57
drill bit size.