DIN 439Hexagon thin nutExternal hexagon

DIN 439 M14 Hexagon thin nut

DIN 439 M14 is a hexagon thin nut, on a M14 × 1.5 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 M14s 21m 7
DIN 439 M14 — Hexagon thin nutNominal dimensions in mm · Not to scale
Diameter14 mm
Pitch1.5 mm
Socket size s21 mm
Height m7 mm
DriveExternal hexagon

Dimensions

Standard
DIN 439
Type
Hexagon thin nut
Size
M14
Socket size s
21 mm
Height m
7 mm
Drive
External hexagon

Nominal values in millimetres as published in DIN 439. Estimated weight 7.28 g per piece in steel (7.327 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.

DesignationM14 × 1.5 fine
Pitch1.5 mm
Nominal Ø14 mm
Pitch Ø13.03 mm
Minor Ø ext12.16 mm
Tap drillØ 12.5 mm

Other lengthsDIN 439 M14

All M14 specifications

Interchangeability

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

Choosing and fitting this size

DIN 439 M14 is a M14 nut, on a 1.5 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, M14 × 1.5 mm takes a 12.5 mm tap drill, and the external thread's minor diameter is 12.16 mm — that is the section carrying the load, not the nominal M14 figure. Thread engagement of at least one times the nominal diameter is what lets the bolt fail before the thread strips.