Number drill · #5
#5 Drill Bit Size — Decimal Inch, Millimetre and Tap Sizes
https://shopmath.org/drills/number/5 · data verified August 1, 2026
A #5 drill bit is 0.2055 in (5.220 mm) in diameter. The nearest fractional size is 13/64" at 0.2031 in. Diameters are nominal.
- Series
- Number
- Designation
- #5
- Inch
- 0.2055
- mm
- 5.220
- Standard
- ANSI/ASME B94.11M
Number Drill · #5 · nominal diameter
0.2055 in
- Millimetre
- 5.220mm
Nominal diameter. A worn or run-out drill cuts oversize, which leaves less thread in a tapped hole than the table says.
#5 Drill Bit Size in Inches and Millimetres
The nominal diameter of a #5 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.
| Property | Value |
|---|---|
| Diameter, decimal inch | 0.2055 in |
| Diameter, millimetre | 5.220 mm |
| Cross-sectional area | 0.03317 in² |
1 in = 25.4 mm exactly, so the two columns are the same value in different units, not two measurements.
#5 Drill Bit Equivalents in Every Other Drill Series
The closest size to the #5 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.
| Property | Property | Diameter | Property | |
|---|---|---|---|---|
| Drill | Series | in | mm | Difference, in |
| A | Letter | 0.2340 | 5.944 | +0.0285 |
| 13/64" | Fractional | 0.2031 | 5.159 | −0.0024 |
| 5.2 mm | Metric | 0.2047 | 5.200 | −0.0008 |
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 #5 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.
Sources and Method for the #5 Drill Bit Size
- Drill diametercompiled
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
Compiled from independent public sources that agree cell-for-cell.
- 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 to Cite This #5 Drill Bit Reference
Citation
ShopMath. "#5 Drill Bit Size — Decimal Inch, Millimetre and Tap Sizes." ShopMath, verified August 1, 2026, https://shopmath.org/drills/number/5
BibTeX
@misc{shopmath-drills-number-5,
title = {#5 Drill Bit Size — Decimal Inch, Millimetre and Tap Sizes},
author = {{ShopMath}},
year = {2026},
howpublished = {\url{https://shopmath.org/drills/number/5}},
note = {Data verified 2026-08-01}
}Permanent URL
https://shopmath.org/drills/number/5
Common Questions About the #5 Drill Bit
What size is a #5 drill bit?
- A #5 drill bit is 0.2055 in in diameter, which is 5.220 mm.
What is the metric equivalent of a #5 drill bit?
- The closest metric drill to a #5 drill bit (5.220 mm) is 5.2 mm, which is 5.200 mm — 0.0008 in smaller.
What fraction is a #5 drill bit closest to?
- A #5 drill bit (0.2055 in) sits closest to the 13/64" fractional drill at 0.2031 in, a difference of 0.0024 in.
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