number drill · nominal diameter

#49
drill bit size.

A #49 bit measures 0.0730 in across (1.854 mm).

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

Diameter conversion cross-checked

Calibrated relative diameter · 1 in reference

#49 · number

0.0730 in

1.854 mm

Designation#49number

Inch decimal0.0730nominal

Metric conversion1.854millimetres

Where this size sits from 0 to 1 inch

#49 · 1.854 mm on a zero to 25.4 millimetre scale. Neighbor marks: 1.9 mm, 1.8 mm.

0 25.4 mm

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Measured neighbors

What sits beside #49.

“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

1.9 mmmetric 0.0748 inΔ +0.046 mm 1.8 mmmetric 0.0709 inΔ -0.054 mm 5/64fractional 0.0781 inΔ +0.130 mm 2 mmmetric 0.0787 inΔ +0.146 mm

Same seriesNEAREST NOMINAL ROWS

#50number 1.778 mmΔ -0.076 mm #48number 1.930 mmΔ +0.076 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

#49drill bit size.

What sits beside #49.

ASME.

#49
drill bit size.