Dimensions Chart for Metric Hex Flange Nut with Coarse Thread according to the ISO 4161 standard.

Some important notes from the ISO standard:

- ISO 4161 specifies the characteristics of hexagon nuts with flange, with metric coarse threads from M5 to M20 inclusive, with product grade A for threads d ≤ M16 and product grade B for threads d > M16.

- Mechanical properties of ISO 4161 metric hex flange nuts: Steel - Property class 8, 9, 10 and 12. Stainless steel - Property class A2-70

Metric Hex Flange Nut with Coarse Thread Dimensions:

Nominal metric hex flange nut size


Dimensions of Metric Hex Flange Nuts
Size ---
Product Grade ---
Standard ---
Pitch ---
cmin ---
da max ---
da min ---
dc max ---
dw min ---
e min ---
m max ---
m min ---
mw min ---
smax ---
smin ---
rmax ---

Note 1: Dimensions are in mm.

Note 2: Requirements for electroplating are covered in ISO 4042 for steel nuts

Note 3: Radius r applies both at the corners and the flats of the hexagon.

Note 4: Thread tolerance of hex flange nuts is 6H.


Product Grade A, Grade B and Grade C: The product grades refer to the size of the tolerances where grade A is the most precise and grade C is the least precise as defined in the ISO 4759-1:2000 standard.


Link Usage
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.
Metric Hex Flange Nut Dimensions - Fine Pitch Thread Shows dimensions of a selected hex flange nut with fine pitch thread.
Nut Grades, Identification Markings and Strength (Metric) Shows proof strength and Vickers and Brinell hardness values of metric nuts made of carbon steel and alloy steel.


  • ISO 4161:1999, Hexagon nuts with flange — Coarse thread
  • ISO 4759-1:2000, Hexagon nuts — Bolts, screws, studs and nuts — Product grades A, B and C