Metric hex socket button head screw dimensions are shown in the following chart according to ISO 7380-1:2011 standard.

ISO 7380-1 specifies the properties of hex socket button screws with thread from M3 up to and including M16.

Some important notes from ISO 7380-1 standard:

- Thread: 5g6g for Grade 12.9, 6g for other classes

- Mechanical Properties: For steel socket button screws, property classes are 8.8, 10.9 and 12.9. For stainless steel socket button screws, property classes are A2-70, A3-70, A4-70 and A5-70, A2-80, A3-80, A4-80 and A5-80.

- Finish: For steel screws, electroplating per ISO 4042 and zinc flake coatings per ISO 10683. For stainless steel screws, plain finish.

- Designation: Hexagon socket button head screw ISO 7380-1 - M12 x 40 - 10.9 (M12 thread with 40 mm length and property class 10.9)

Metric hex socket button head screw sizes and dimensions:

Thread Size [d]
Nominal Length [l]Note 1

Note 1: The range of commercial lengths is given in the list. Consult manufacturer for availability of other lengths.


Dimensions of Metric Socket Button Screws
Parameter Value
Thread Size d --- ---
Thread Pitch P --- mm
Max. Fillet Transition Diameter da,max ---
Head Diameter [dk] dk,max ---
dk,min ---
Diameter of the Upper Flat Face dL,ref ---
Body Diameter [ds] Note 1 ds,max ---
ds,min ---
Diameter of the Bearing Face dw,min ---
Min. Hexagon Socket Size
Across the Corners
emin ---
Head Height [k] kmax ---
kmin ---
Radius of the Raised
Portion of a Head
rf,max ---
rf,min ---
Underhead Radius for a Screw with Unthreaded Shank rs,min ---
Underhead Radius for a Fully Threaded Screw rt,min ---
Hexagon Socket Size snom ---
smax ---
smin ---
Min. Depth of Driving Feature tmin ---
Min. Thickness between Driving Feature and Bearing Face wmin ---
Screw Length lnom --- mm 
lmax ---
lmin ---
Max. Grip Length lg,max ---
Min. Shank Length ls,min ---
Thread Length bref ---
Note  ---

Note:1 ds applies if values of ls,min are specified.


Link Usage
ISO Metric Thread Calculator Calculates basic major, minor and pitch diameters of the metric external (bolt) thread and internal (nut) thread according to ISO 724:1993 standard. In addition to basic size calculations, tolerance calculations of different tolerance classes can be done according to ISO 965-1:1998 and ISO 965-2:1998 standards.


  • EN ISO 7380-1:2011, Button Head Screws - Part 1: Hexagon Socket Button Head Screws ( ISO 7380-1:2011)