METRIC HEX NUT DIMENSIONS CHART


Metric hex nut dimensions sizes chart according to ISO 4032. All dimensions are given in millimeters. Width across flats (wrench size) and corners, nut height (thickness) and thread pitch dimensions are given for nut sizes between M1.6 to M64.

Metric Hex Nut Dimensions
Nut Size Thread
Pitch
s e m
Width
Across
Flats
Width
Across
Corners
Height
of
the
Nut
max. min. min. max. min.
M1.6 0.35 3.20 3.02 3.41 1.30 1.05
M2 0.4 4.00 3.82 4.32 1.60 1.35
M2.5 0.45 5.00 4.82 5.45 2.00 1.75
M3 0.5 5.50 5.32 6.01 2.40 2.15
M3.5* 0.6 6.00 5.82 6.58 2.80 2.55
M4 0.7 7.00 6.78 7.66 3.2 2.9
M5 0.8 8.00 7.78 8.79 4.7 4.4
M6 1 10.00 9.78 11.05 5.2 4.9
M8 1.25 13.00 12.73 14.38 6.80 6.44
M10 1.5 16.00 15.73 17.77 8.40 8.04
M12 1.75 18.00 17.73 20.03 10.80 10.37
M14* 2 21.00 20.67 23.36 12.8 12.1
M16 2 24.00 23.67 26.75 14.8 14.1
M18* 2.5 27.00 26.16 29.56 15.8 15.1
M20 2.5 30.00 29.16 32.95 18.0 16.9
M22* 2.5 34 33 37.29 19.4 18.1
M24 3 36 35 39.55 21.5 20.2
M27* 3 41 40 45.2 23.8 22.5
M30 3.5 46 45 50.85 25.6 24.3
M33* 3.5 50 49 55.37 28.7 27.4
M36 4 55.0 53.8 60.79 31.0 29.4
M39* 4 60.0 58.8 66.44 33.4 31.8
M42 4.5 65.0 63.1 71.3 34.0 32.4
M45* 4.5 70.0 68.1 76.95 36.0 34.4
M48 5 75.0 73.1 82.6 38.0 36.4
M52* 5 80.0 78.1 88.25 42.0 40.4
M56 5.5 85.0 82.8 93.56 45.0 43.4
M60* 5.5 90.0 87.8 99.21 48.0 46.4
M64 6 95.0 92.8 104.86 51.0 49.1

Note : * Non-preferred threads according to standard.

Supplements:

Link Usage
Metric hex nut dimensions calculator Calculator form of the metric hex nut dimensions chart.

Reference:

  • ISO 4032:1999, Hexagon regular nuts (style 1) — Product grades A and B