Metric Thread Forms and Pitch

 Unless otherwise stated, Anzor's metric fasteners are Coarse Standard

Metric Diameter

Pitch = P (mm)

Coarse Standard

Fine Standard

M2 0.40  
M2.5 0.45   
M3 0.50 0.35
M4 0.70 0.50
M5 0.80 0.75
M6 1.00 0.75
M8 1.25 0.50,1.00
M10 1.50 1.00,1.25
M12 1.75 1.00,1.25,1.50
M14 2.00 1.50
M16 2.00 1.50
M18 2.50 1.50
M20 2.50 1.50,2.00
M22 2.50 1.50
M24 3.00 1.50,2.00
M27 3.00 1.50,2.00
M30 3.50 1.50,2.00
M33 3.50 2.00
M36 4.00 1.50,2.00
M39 4.00 1.50,2.00
M42 4.50 2.00

ISO Metric Thread Form

P = Pitch = 1/Number of threads per inch (tpi)

H = Angular Depth = 0.866025 x P

H/8 = Shortening of major dia = 0.108253 x P

H/4 = Shortening of minor dia = 0.216506 x P

d = Actual Depth = 0.541266 x P

r = Radius at the Root = 0.1443 x P

Hn = Basic height of Internal Thread = 0.54127 x P

Hs = Basic height of External Thread = 0.61344 x P

The form of the Metric Series of Threads varies between Internal & External Threads, in particular the root and crest details. This allows for flat (truncated) or radiused forms. Engineers requiring more specific information should refer to the relevant ISO Standards.