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 Screw Thread Sizes & Tolerances 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)