Metric

(ISO 4017 / DIN 933)

Thread Designation Head Diameter (mm) Head Height (mm) Clearance Hole (mm) Thread Pitch (mm)
M1 2.1 0.8 1.3 0.25
M1.2 2.5 1.0 1.5 0.25
M1.4 3.0 1.2 1.7 0.30
M1.6 3.2 1.1 1.8 0.35
M2 4.0 1.4 2.4 0.40
M2.5 5.0 1.7 2.9 0.45
M3 5.5 2.0 3.4 0.50
M4 7.0 2.8 4.5 0.70
M5 8.0 3.5 5.5 0.80
M6 10.0 4.0 6.6 1.00
M8 13.0 5.3 9.0 1.25
M10 17.0 6.4 11.0 1.50
M12 19.0 7.5 13.5 1.75
M14 22.0 8.8 15.5 2.00
M16 24.0 10.0 17.5 2.00
M18 27.0 11.5 20.0 2.50
M20 30.0 12.5 22.0 2.50
M22 32.0 14.0 24.0 2.50
M24 36.0 15.0 26.0 3.00

Imperial

ASME B18.2.1 - Finished Hex bolts.

Thread Designation Head Diameter (in) Head Height (in) Clearance Hole (in) Threads Per Inch (TPI)
#4-40 1/4" 3/32" 0.128" 40
#6-32 5/16" 7/64" 0.149" 32
#8-32 11/32" 1/8" 0.177" 32
#10-24 3/8" 1/8" 0.204" 24
1/4"-20 7/16" 11/64" 17/64" 20
5/16"-18 1/2" 7/32" 21/64" 18
3/8"-16 9/16" 1/4" 25/64" 16
7/16"-14 5/8" 19/64" 29/64" 14
1/2"-13 3/4" 11/32" 17/32" 13
5/8"-11 15/16" 27/64" 21/32" 11
3/4"-10 1-1/8" 1/2" 25/32" 10
7/8"-9 1-5/16" 37/64" 29/32" 9
1"-8 1-1/2" 43/64" 1-1/16" 8