DIN 439Hexagon thin nutExternal hexagon

DIN 439 M4 Hexagon thin nut

DIN 439 M4 is a hexagon thin nut, on a M4 × 0.7 mm metric thread. A low profile hex nut used as a lock nut against a full nut, or where axial space is tight. Because it carries fewer threads it is not rated for full service load on its own.

Dimensioned drawing — DIN 439 M4s 7m 2.2
DIN 439 M4 — Hexagon thin nutNominal dimensions in mm · Not to scale
Diameter4 mm
Pitch0.7 mm
Socket size s7 mm
Height m2.2 mm
DriveExternal hexagon

Dimensions

Standard
DIN 439
Type
Hexagon thin nut
Size
M4
Thread
M4 × 0.7
Socket size s
7 mm
Height m
2.2 mm
Drive
External hexagon

Nominal values in millimetres as published in DIN 439. Estimated weight 0.333 g per piece in steel (0.335 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.

Thread data

Full M4 thread page
DesignationM4 × 0.7
Pitch0.7 mm
Nominal Ø4 mm
Pitch Ø3.55 mm
Minor Ø ext3.14 mm
Tap drillØ 3.3 mm

Other lengthsDIN 439 M4

All M4 specifications
M4

Interchangeability

DIN 439 is catalogued with ISO 4035 as its equivalent designation. Dimensions are compared field by field rather than assumed identical.

Equivalent standardISO 4035Hexagon Thin Nut, ChamferedComparisonDIN 439 vs ISO 4035Field-by-field differences and a substitution verdict

Choosing and fitting this size

DIN 439 M4 is a M4 nut, on a 0.7 mm coarse pitch. Mating threads should be a matching class nut in the same property class.

Common stock grades are 8.8, 10.9 and 12.9 in steel, plus A2-70 and A4-80 in stainless. Class 10.9 and 12.9 carry roughly 1.25 and 1.5 times the proof load of 8.8, but they also need a properly rated mating nut — a class 8 nut under a 12.9 bolt simply moves the failure into the thread. Zinc-plated 10.9 and above should be baked to avoid hydrogen embrittlement.

For a tapped hole, M4 × 0.7 mm takes a 3.3 mm tap drill, and the external thread's minor diameter is 3.14 mm — that is the section carrying the load, not the nominal M4 figure. Thread engagement of at least one times the nominal diameter is what lets the bolt fail before the thread strips.