DIN nuts & special nuts – reliable, standardized, and custom-made

The hexagon nut to DIN 934 (now ISO 4032) is a standardized nut with a metric standard thread. It is used in combination with screws of strength classes 8.8, 10.9 or 12.9 and is intended for general screw connections without additional locking.

Differentiation: In contrast to DIN 985 (with polyamide locking) or DIN 439 (flat design), DIN 934 has a normal installation height and no locking elements. It can be used universally, but is not suitable for dynamically loaded connections without additional locking.

ASME B18.2.2 defines dimensions and tolerances for heavy hex nuts with unified inch threads (UNC, UNF, 8UN). The nuts have larger widths across flats and heights than standard hex nuts and are frequently used in steel construction and mechanical engineering.

Differentiation: Compared to regular hex nuts (e.g. to DIN 934 / ISO 4032), Heavy Hex Nuts have a more solid design, offer a larger contact surface and higher preload forces - ideal for high-strength screw connections to ASTM A325 or A490.

DIN 431 describes pipe nuts with a cylindrical pipe thread (G-thread) in accordance with DIN EN ISO 228-1. Form A stands for the version without thread countersink. These nuts are mainly used in pipeline construction, e.g. for fastening screw connections or fittings.

Differentiation: In contrast to form B (with thread countersink on one side), form A is flat. It also differs from metric nuts such as DIN 934 due to the imperial pipe thread and the flatter design.

DIN 439 Form B describes a low hexagon nut with a metric standard or fine pitch thread and a chamfer on both ends. It is often used as a lock nut, e.g. to secure screw connections against self-loosening.

Differentiation: Compared to DIN 934, DIN 439 type B is significantly lower and therefore not suitable for high-strength connections. Compared to form A, form B has a chamfer, which improves handling and rounds off the edges.

DIN 6330 describes a high hexagon nut (1.5 × nominal diameter) with a spherical bearing surface on one side (form B). It is used, for example, in clamping devices or machine assemblies where screw connections are frequently loosened and tightened again.

Differentiation: Compared to DIN 934, it is higher and has a spherical bearing surface that compensates for positional deviations - ideal for dynamically stressed connections.

DIN 917 describes hexagon cap nuts with a low profile and metric internal thread. They are characterized by the closed, dome-shaped end that covers the free thread end. These nuts are often used to visually round off screw connections and at the same time protect them from dirt, moisture and damage.

Differentiation: Compared to DIN 1587 (cap nut, normal shape), DIN 917 is lower and therefore suitable for applications with limited installation space. It does not offer a locking function, but protects the end of the thread and reduces the risk of injury.

DIN 936 describes a flat hexagon nut with a metric standard or fine pitch thread. It is used when installation space is limited or a lock nut is required. The low height saves space without impairing the function of the screw connection.

Differentiation: Flatter than DIN 934, but higher than DIN 439. No locking function, but suitable as a space-saving nut or lock nut.

DIN 6923 describes hexagon nuts with an integrated flange that serves as a fixed washer. The wide flange increases the contact surface, distributes the contact pressure evenly and protects the workpiece from point loads.

Differentiation: Compared to DIN 934, the flange nut offers better force distribution and increased protection against self-loosening - especially in the event of vibrations or on soft materials. An additional washer is usually not required.

DIN 980 describes hexagon nuts with an integrated locking function. Thanks to a special deformation in the upper thread area, it offers increased security against self-loosening - even under vibrations and dynamic loads. Locking is purely mechanical, without additional elements such as adhesive or plastic rings.

Differentiation: Compared to standard hexagon nuts to DIN 934, DIN 980 reliably prevents the connection from loosening and is ideal for safety-relevant applications in mechanical engineering and vehicle construction.

DIN 1587 describes hexagon cap nuts with a metric internal thread and dome-shaped, closed head. This protects the free thread end from dirt, moisture and mechanical damage and gives the connection a visually clean finish.

Differentiation: Compared to DIN 917 (low form), DIN 1587 is higher and is suitable for applications where the thread end needs to be completely covered. It does not provide a locking function, but reduces the risk of injury and improves the appearance.