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Fractional drill · 1/32

1/32" Drill Bit Size — Decimal Inch, Millimetre and Tap Sizes

A 1/32" drill bit is 0.0313 in (0.794 mm) in diameter. Diameters are nominal.

Series
Fractional
Designation
1/32
Inch
0.0313
mm
0.794
Standard
ANSI/ASME B94.11M

Fractional Drill · 1/32 · nominal diameter

0.0313 in

Millimetre
0.794mm
Fraction
1/32in

Nominal diameter. A worn or run-out drill cuts oversize, which leaves less thread in a tapped hole than the table says.

1/32" Drill Bit Size in Inches and Millimetres

The nominal diameter of a 1/32" drill bit. Drill sizes are nominal — a worn drill, run-out or a soft material that closes in behind the cut all move the finished hole.

1/32" drill bit — decimal inch and millimetre diameter
PropertyValue
Diameter, decimal inch0.0313 in
Diameter, millimetre0.794 mm
Fraction1/32 in
Cross-sectional area0.00077 in²

1 in = 25.4 mm exactly, so the two columns are the same value in different units, not two measurements.

1/32" Drill Bit Equivalents in Every Other Drill Series

The closest size to the 1/32" drill bit in each of the other three indexes, with the difference in inches. None of them is the same drill — check the difference before substituting one into a tapped hole.

Nearest number, letter, fractional and metric equivalents to a 1/32" drill bit
PropertyPropertyDiameterProperty
DrillSeriesinmmDifference, in
#68Number0.03100.787−0.0003
ALetter0.23405.944+0.2028
0.8 mmMetric0.03150.800+0.0002

A positive difference means the equivalent drill is larger, which leaves less thread in a tapped hole. Sizes without a link are stored for the nearest-drill calculation but do not carry their own page.

Drill Sizes Either Side of the 1/32" Drill Bit

Ordered by diameter across all four indexes, so the next size up may be a letter, a fraction or a metric drill rather than the next one in this series.

Standard drill sizes adjacent to a 1/32" drill bit, by diameter
PropertyPropertyDiameter
DrillSeriesinmm
0.75 mmMetric0.02950.750
0.78 mmMetric0.03070.780
1/32"Fractional0.03130.794
0.8 mmMetric0.03150.800
0.82 mmMetric0.03230.820

Sources and Method for the 1/32" Drill Bit Size

Drill diametercomputed

Number/letter: bd_warehouse drill_sizes.csv (Apache-2.0) cross-checked against Wikipedia Drill bit sizes (CC BY-SA 4.0). Fractional: computed 1/64 in steps per ANSI B94.11M. Metric: computed BS 328 increment pattern.

Verified against Wikipedia Drill bit sizes (CC BY-SA 4.0); 31/31 checks passed

Computed from the standard's formulas, then checked against published tables.

Formula

Fractional drill diameter

Ø  =  1/32 in  =  0.0313 in

Fractional drills are exact fractions of an inch in 1/64 in steps; the decimal is the fraction evaluated, not a measurement.

Assumptions
  • Diameters are nominal. Drill manufacturing tolerance, wear and run-out all cut oversize, and every one of those moves a tapped hole toward less thread than the table says.
  • Dataset scope: Number sizes #61-#80 are stored but tagged demandTier 'extended' — query-space-map.md Appendix A found the tail thinning in the 60s. Sizes below #80 and metric sizes above 25.0 mm excluded.
Data last verified
August 1, 2026
How this data is built and checked →

How to Cite This 1/32" Drill Bit Reference

Citation

ShopMath. "1/32" Drill Bit Size — Decimal Inch, Millimetre and Tap Sizes." ShopMath, verified August 1, 2026, https://shopmath.org/drills/fractional/1-32

BibTeX

@misc{shopmath-drills-fractional-1-32,
  title        = {1/32" Drill Bit Size — Decimal Inch, Millimetre and Tap Sizes},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/drills/fractional/1-32}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/drills/fractional/1-32

Common Questions About the 1/32" Drill Bit

What size is a 1/32" drill bit?

A 1/32" drill bit is 0.0313 in in diameter, which is 0.794 mm. It is the 1/32 in fractional size.

What is the metric equivalent of a 1/32" drill bit?

The closest metric drill to a 1/32" drill bit (0.794 mm) is 0.8 mm, which is 0.800 mm — 0.0002 in larger.

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