DIN 985 Hexagon Lock Nut with Nylon Insert is a low-profile prevailing torque lock nut designed to prevent loosening caused by vibration and dynamic loads. It features a built-in non-metallic nylon locking ring that provides resistance to the bolt threads, delivering reliable anti-loosening performance without additional locking elements.

Compared with standard hex nuts, it integrates a nylon ring inside the nut body. When tightened, the nylon insert deforms slightly and grips the bolt thread, increasing friction and preventing accidental loosening.

The low-profile design reduces the overall installation height, making it suitable for applications with limited space while still providing reliable locking performance.

Also known as a Nyloc Nut / Nylon Insert Lock Nut / Self-Locking Hex Nut, DIN 985 is widely used in automotive, machinery, electrical equipment, furniture, and general industrial fastening applications. 

DIN 982 and DIN 985 are both nylon insert lock nuts, but their main difference is the nut height.

• DIN 982: High type nylon lock nut, providing deeper thread engagement and higher load capacity.
• DIN 985: Standard type nylon lock nut, more compact and suitable for general applications.

DIN 982 is preferred where stronger locking performance and higher mechanical strength are required.

Higher Strength and Load Capacity
DIN 982 is a high-form nylon insert lock nut, while DIN 985 is the standard low-form nylon insert lock nut. The increased height of DIN 982 provides longer thread engagement, resulting in better resistance to shear forces and higher mechanical loads.

Better Performance in Heavy-Duty Applications
Due to its thicker nut body and greater engagement length, DIN 982 offers improved structural strength and is more suitable for applications exposed to heavy loads, vibration, and dynamic stress. DIN 985 is generally preferred for standard fastening applications where space-saving is required.

Improved Reusability
Both DIN 982 and DIN 985 use a nylon insert to generate locking torque without damaging the bolt thread. However, the larger body size of DIN 982 provides better durability during repeated assembly and disassembly.

Application Difference

• DIN 982: Recommended for machinery, automotive components, industrial equipment, and applications requiring higher fastening reliability.
• DIN 985: Suitable for general mechanical assemblies, electrical equipment, and applications with limited installation space.