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Fractional drill · 11/64

11/64" Drill Bit Size — Decimal Inch, Millimetre and Tap Sizes

A 11/64" drill bit is 0.1719 in (4.366 mm) in diameter. Diameters are nominal.

Series
Fractional
Designation
11/64
Inch
0.1719
mm
4.366
Standard
ANSI/ASME B94.11M

Fractional Drill · 11/64 · nominal diameter

0.1719 in

Millimetre
4.366mm
Fraction
11/64in

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

11/64" Drill Bit Size in Inches and Millimetres

The nominal diameter of a 11/64" 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.

11/64" drill bit — decimal inch and millimetre diameter
PropertyValue
Diameter, decimal inch0.1719 in
Diameter, millimetre4.366 mm
Fraction11/64 in
Cross-sectional area0.02320 in²

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

11/64" Drill Bit Equivalents in Every Other Drill Series

The closest size to the 11/64" 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 11/64" drill bit
PropertyPropertyDiameterProperty
DrillSeriesinmmDifference, in
#17Number0.17304.394+0.0011
ALetter0.23405.944+0.0621
4.4 mmMetric0.17324.400+0.0014

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 11/64" 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 11/64" drill bit, by diameter
PropertyPropertyDiameter
DrillSeriesinmm
4.3 mmMetric0.16934.300
#18Number0.16954.305
11/64"Fractional0.17194.366
#17Number0.17304.394
4.4 mmMetric0.17324.400

Sources and Method for the 11/64" 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  =  11/64 in  =  0.1719 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 11/64" Drill Bit Reference

Citation

ShopMath. "11/64" Drill Bit Size — Decimal Inch, Millimetre and Tap Sizes." ShopMath, verified August 1, 2026, https://shopmath.org/drills/fractional/11-64

BibTeX

@misc{shopmath-drills-fractional-11-64,
  title        = {11/64" Drill Bit Size — Decimal Inch, Millimetre and Tap Sizes},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/drills/fractional/11-64}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/drills/fractional/11-64

Common Questions About the 11/64" Drill Bit

What size is a 11/64" drill bit?

A 11/64" drill bit is 0.1719 in in diameter, which is 4.366 mm. It is the 11/64 in fractional size.

What is the metric equivalent of a 11/64" drill bit?

The closest metric drill to a 11/64" drill bit (4.366 mm) is 4.4 mm, which is 4.400 mm — 0.0014 in larger.

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