Castle nuts DIN 935

DIN 935 nuts for machines and mechanical connections

Castle nuts have slots that permit split-pin use in a suitably designed connection. This arrangement is found in fastenings on axles and shafts and in machine assemblies where documentation specifies mechanical location of the nut. Selection for an assembly depends on the design requirements.

Coarse and fine-pitch threads

The NERON catalogue has separate groups of DIN 935 nuts with a coarse metric thread and DIN 935 nuts with a fine-pitch thread. In both cases, nominal diameter and thread pitch must be known. Matching diameter is insufficient if the nut and screw pitches differ.

How do you select the nut and split pin?

• Thread: check the complete designation, including pitch.
• Nut dimensions: account for height, width across flats and slot geometry.
• Hole in the screw or shaft: its position must allow engagement with the nut slots after the connection is set according to instructions.
• Split pin: match its size and design to the hole, slots and assembly documentation.
• Material and strength: match them to mating components, loads and the operating environment.

Rotational locking and connection setting

The split pin is a mechanical locking component. It does not replace correct setting of clamping force, clearance or tightening torque. The assembly instructions should determine how slots and hole are aligned. In bearing arrangements, maintaining the required clearance or preload is particularly important.

Questions about castle nuts DIN 935

Does a castle nut lock itself?
Slot shape alone is insufficient. A connection designed for this solution needs the correct locking component and a hole in the mating part.

Can DIN 935 be replaced by a thin castle nut?
This requires comparing height, mechanical properties and split-pin hole position. Reduced height does not mean automatic interchangeability.

How do you prepare an enquiry for NERON in Piła?
State DIN 935, thread diameter and pitch, material, required properties and quantity. For replacement, a drawing, previous nut designation and hole and split-pin dimensions are useful.

Other types are in the section for castle nuts.