What size is a 2 mm drill bit?

A 2 mm drill bit is 0.0787 in in diameter, which is 2.000 mm.

What fraction is a 2 mm drill bit closest to?

A 2 mm drill bit (0.0787 in) sits closest to the 5/64" fractional drill at 0.0781 in, a difference of 0.0006 in.

What bolt fits through a 2 mm drill bit hole?

A hole drilled with a 2 mm drill bit is the standard loose clearance hole for M1.6×0.2, and a clearance hole for 3 other fastener sizes listed on this page.

Metric drill · 2 mm

2 mm Drill Bit Size — Decimal Inch, Millimetre and Tap Sizes

https://shopmath.org/drills/metric/2mm · data verified August 1, 2026

A 2 mm drill bit is 0.0787 in (2.000 mm) in diameter. The nearest fractional size is 5/64" at 0.0781 in. Diameters are nominal.

Series: Metric
Designation: 2 mm
Inch: 0.0787
mm: 2.000
Standard: ANSI/ASME B94.11M

Metric Drill · 2 mm · nominal diameter

0.0787 in

Millimetre: 2.000mm

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

2 mm Drill Bit Size in Inches and Millimetres

The nominal diameter of a 2 mm 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.

2 mm drill bit — decimal inch and millimetre diameter
Property	Value
Diameter, decimal inch	0.0787 in
Diameter, millimetre	2.000 mm
Cross-sectional area	0.00487 in²

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

Threads a 2 mm Drill Bit Taps

Every thread in this reference whose tap drill is the 2 mm drill bit, and the thread engagement it leaves. The engagement asked for and the engagement the drill actually produces are different numbers — that gap is why both columns are here.

Threads tapped with a 2 mm drill bit, by thread engagement
Thread	Series	Thread % asked for	Thread % this drill leaves
M2.5×0.45	ISO Metric Coarse	85%	85.5

Values are for cut taps. Rows marked default are the shop-default engagement for that thread.

Fasteners That Pass Through a 2 mm Drill Bit Hole

A hole drilled with a 2 mm drill bit is the standard clearance hole for these fasteners — the through-hole the bolt passes freely, not the tapped hole.

Fasteners whose clearance hole is drilled with a 2 mm drill bit
Fastener	Series	Clearance class
M1.6×0.2	ISO Metric Fine	loose
M1.6×0.35	ISO Metric Coarse	loose
M1.8×0.2	ISO Metric Fine	close
M1.8×0.35	ISO Metric Coarse	close

Clearance classes per ISO 273 (metric) and ASME B18.2.8 (inch): close for located joints, normal for general assembly, loose for slotted or adjustable joints.

2 mm Drill Bit Equivalents in Every Other Drill Series

The closest size to the 2 mm 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 2 mm drill bit
Property	Property	Diameter		Property
Drill	Series	in	mm	Difference, in
#47	Number	0.0785	1.994	−0.0002
A	Letter	0.2340	5.944	+0.1553
5/64"	Fractional	0.0781	1.984	−0.0006

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 2 mm 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 2 mm drill bit, by diameter
Property	Property	Diameter
Drill	Series	in	mm
5/64"	Fractional	0.0781	1.984
#47	Number	0.0785	1.994
2 mm	Metric	0.0787	2.000
2.05 mm	Metric	0.0807	2.050
#46	Number	0.0810	2.057

Sources and Method for the 2 mm 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.

Tap drill usagecomputed+compiled

bd_warehouse drill_sizes.csv (Apache-2.0) + Wikipedia Drill bit sizes (CC BY-SA 4.0); fractional and metric computed from ANSI B94.11M / BS 328 increment patterns

Verified against drills: 31 checks passed across 1 harness(es)

Part computed from the standard's formulas, part compiled from agreeing public sources.

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 2 mm Drill Bit Reference

Citation

ShopMath. "2 mm Drill Bit Size — Decimal Inch, Millimetre and Tap Sizes." ShopMath, verified August 1, 2026, https://shopmath.org/drills/metric/2mm

BibTeX

@misc{shopmath-drills-metric-2mm,
  title        = {2 mm Drill Bit Size — Decimal Inch, Millimetre and Tap Sizes},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/drills/metric/2mm}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/drills/metric/2mm

Common Questions About the 2 mm Drill Bit

What size is a 2 mm drill bit?: A 2 mm drill bit is 0.0787 in in diameter, which is 2.000 mm.
What fraction is a 2 mm drill bit closest to?: A 2 mm drill bit (0.0787 in) sits closest to the 5/64" fractional drill at 0.0781 in, a difference of 0.0006 in.
What bolt fits through a 2 mm drill bit hole?: A hole drilled with a 2 mm drill bit is the standard loose clearance hole for M1.6×0.2, and a clearance hole for 3 other fastener sizes listed on this page.

All metric drill sizes · Complete drill size chart · Every drill series