Slotted nut | A2 | DIN 1804

Do you need a nut that functions reliably even in damp environments and outdoors? Stainless steel A2 hook nut according to DIN 1804 is built to resist corrosion and maintain strength over a long period. It combines wear resistance with high structural integrity and is optimized to withstand both heavy mechanical loads and frequent use.

AREA OF APPLICATION

Perfect for mounting, fixing, and securing shafts, bearings, and machine parts in industry, machine construction, and other environments where rust protection is critical. The design of the hook nut makes it easy to mount and loosen with a hook spanner, while providing a stable and vibration-resistant fastening. Requires minimal maintenance even during continuous operation.

TECHNICAL SPECIFICATIONS

Product type: Hook nut
Standard: DIN 1804
Quality: Stainless steel A2
Material class: Not specified
Thread type: Metric thread
Surface treatment: Untreated (natural colored stainless steel)
Head shape: Round with hook slots
Grip type: Hook slots for hook spanner

FREQUENTLY ASKED QUESTIONS (FAQ)

What is a hook nut (DIN 1804) and how is it mounted correctly?

A hook nut is a round nut equipped with notches (slots) in the outer edge instead of a standard hexagonal grip. It is primarily used to lock or adjust axial positions on shafts, bearing seats, and spindles. Mounting and tightening are performed with a specially adapted hook spanner that grips the nut's outer slots, which allows for controlled torque even in tight spaces.

Why are DIN 1804 hook nuts often used for adjusting bearings and shafts?

The hook nut has a low profile and a flat contact surface that provides a very precise axial lock against rolling bearings, bushings, or other rotating components. The design makes it possible to fine-tune play and preload in bearing assemblies without the nut protruding or adding excessive weight.

When is stainless steel A2 (AISI 304) sufficient and when should A4 be chosen instead?

Stainless A2 steel (AISI 304 / 1.4301) provides excellent corrosion protection for outdoor use, industrial machinery, and damp indoor environments. A2 handles rain, freshwater, and mild chemicals perfectly. However, if the hook nut is to be in direct contact with salt water (marine installations), acids, or aggressive chemicals, acid-proof A4 (AISI 316) is recommended to prevent pitting.