M5 tap drill size

Drill a 4.2 mm hole (0.1654") for an M5 × 0.8 tap. That leaves about 77% thread, the standard for general-purpose tapping.

Tap drill
4.2 mm
0.1654" · 4.20 mm · 77% thread
Inch drill
#19 75% thread
Clearance (close)
5.3 mm
Heat-set insert hole
6.40 mm
Helicoil (STI) drill
5.2 mm
M5 tap drill: 4.2 mm (0.1654 in / 4.20 mm), 77% thread

M5 thread specs

SeriesISO metric coarse
Major diameter5.00 mm (0.1969")
Pitch0.8 mm (31.7 TPI)
Basic minor diameter4.13 mm (0.1628")
Common internal class6H

Every drill that works for M5

Drills from all four sets that give 50–85% thread, largest first. Lower percentages tap easier; see how much thread you need.

DrillThreadinmmSetGood for
4.4 mm58%0.17324.40Metricdeep holes only
#1758%0.17304.39Numberdeep holes only
11/64"61%0.17194.37Fractionalhard or tough metals
#1867%0.16954.31Numberhard or tough metals
4.3 mm67%0.16934.30Metrichard or tough metals
#1975%0.16604.22Numbergeneral use
4.2 mmstandard77%0.16544.20Metricgeneral use

M5 clearance hole

The hole a M5 screw passes through. ISO 273 fine, medium and coarse series.

Fitmmin
Close (fine)5.3 mm0.2087
Normal (medium)5.5 mm0.2165
Loose (coarse)5.8 mm0.2283

M5 counterbore and countersink

For a socket head cap screw to sit flush, and for a flat head socket screw.

Socket head counterboreDiameterDepth
NBK9.50 mm5.40 mm
AMES9.75 mm5.00 mm

Flat head socket screw: countersink at 90° (metric screws, ISO 10642) to 11.20 mm (0.4409") across for a flush head. Inch flat heads use 82°, so don't mix countersinks.

M5 heat-set insert hole

Hole to model for a brass heat-set insert in a 3D print. Brands size their knurl differently, so use your brand’s number.

BrandHoleInsert lengthMin. wall
CNC Kitchen6.40 mm––
ruthex6.40 mm9.5 mm2.6 mm
Accu6.40 mm––
Generic (Albany County)6.40 mm––

M5 holes in a 3D print

Printed holes usually come out undersize. Model the hole at the drill size plus what your printer loses, then tap or drill to size. Why printed holes shrink.

Print a test hole, measure it with calipers, enter the difference. 0 models the nominal size.

Hole to tap
4.20 mm
Clearance hole
5.30 mm
Heat-set insert
6.40 mm

M5 thread repair (Helicoil)

Stripped M5 thread? Drill out with the STI drill, tap with a M5 × 0.8 STI tap, and fit a wire thread insert. The drill in your repair kit’s instructions wins over any chart.

ChartSTI drillinmm
MISUMI5.2 mm0.20475.20

Related sizes

M4next size downM6next size up10-24closest inchFull chartmetric coarse

Frequently asked questions

What size drill do I use for an M5 tap?
Use a 4.2 mm (4.20 mm / 0.1654 in) drill. It leaves about 77% thread, the standard for general-purpose tapping.
What inch drill can I use for an M5 tap?
#19 (4.22 mm / 0.1660 in) is the closest, giving about 75% thread. Anything from about 65% to 80% thread taps well in most materials.
What size clearance hole for an M5 screw?
5.3 mm (5.30 mm) for a close fit, 5.5 mm (5.50 mm) for a normal fit.
What hole size for an M5 heat-set insert?
6.4 mm in the brands listed here. Check your insert's own listing; the hole is sized for that insert's knurl.
What is the inch equivalent of M5?
10-24 is the closest size (4.83 mm vs 5.00 mm major diameter). The pitches differ, so the screws and tapped holes are not interchangeable.

Sources

Spotted a wrong number? Email contact@clove3d.com and it gets fixed.

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% thread = (major − drill) ÷ (1.299 × pitch) × 100. The standard drill comes from published charts and is checked against this formula on every build.