Metric

(DIN 562 / DIN 557) Square nuts provide a greater surface contact area than hex nuts, making them ideal for sliding into channels or for use in wood where they are less likely to spin.

Thread Designation Width (mm) Thickness (mm) Thread Pitch (mm)
M2 4.0 1.2 0.40
M2.5 5.0 1.6 0.45
M3 5.5 1.8 0.50
M4 7.0 2.2 0.70
M5 8.0 2.7 0.80
M6 10.0 3.2 1.00
M8 13.0 4.0 1.25
M10 16.0 5.0 1.50
M12 18.0 10.0 1.75
M14 22.0 11.0 2.00
M16 24.0 13.0 2.00
M20 30.0 16.0 2.50
M24 36.0 19.0 3.00

Imperial

(ANSI/ASME B18.2.2)

Thread Designation Width Across Flats (in) Nut Height (in) Threads Per Inch (TPI)
#0-80 5/32" 3/64" 80
#2-56 3/16" 1/16" 56
#4-40 1/4" 3/32" 40
#6-32 5/16" 7/64" 32
#8-32 11/32" 1/8" 32
#10-24 3/8" 1/8" 24
1/4"-20 7/16" 7/32" 20
5/16"-18 9/16" 17/64" 18
3/8"-16 5/8" 21/64" 16
7/16"-14 3/4" 3/8" 14
1/2"-13 13/16" 7/16" 13
5/8"-11 1" 35/64" 11
3/4"-10 1-1/8" 21/32" 10
7/8"-9 1-5/16" 49/64" 9
1"-8 1-1/2" 7/8" 8