I. Core Function Differences

Common nuts: They achieve basic connection solely through the frictional force between the threads and the bolt, without any specific anti-loosening design. Under conditions such as vibration, impact, and temperature changes, the frictional force between the threads is prone to decrease, causing the nut to loosen and even resulting in the failure of the connection.

Locking nuts: Through different structures or designs, they actively enhance the anti-loosening capability, ensuring the stability of the connection even under harsh conditions, thereby reducing the risk of loosening.

II. Differences in Applicable Scenarios

Regular nuts: Suitable for static, low-vibration, and non-shock scenarios, such as securing non-moving components (such as equipment shells, supports), and with a low requirement for connection reliability. They can be inspected and maintained regularly.

Locking nuts: Suitable for dynamic, high-vibration, impact-prone or difficult-to-maintain scenarios, such as:

High-frequency vibrating components such as the car chassis and engine;

The connection area between engineering machinery and rail transportation;

For situations where equipment at high altitudes or for steel structures of bridges cannot be frequently maintained and repaired.

III. Differences in Usage Cost and Lifespan

Cost: The anti-loosening nut has a more complex structure (requiring additional processing or assembly of anti-loosening components), and thus its cost is usually higher than that of a regular nut (approximately 2-5 times that of a regular nut, depending on the type).

Life and Reusability:

- Ordinary nuts: Can be repeatedly disassembled and used without loss of performance, and have a longer service life;

Anti-loosening nuts: Some types are "one-time" (such as flattened type, punched type), and the anti-loosening structure will fail after removal, requiring replacement; reusable types (such as nylon insert nuts) will also have a shorter lifespan than ordinary nuts due to the aging of anti-loosening components (such as wear of nylon rings).

IV. Differences in Installation and Disassembly

Installation:

- Ordinary nuts: Just tighten them directly; the requirement for torque accuracy is relatively low.

Anti-loosening nuts: They should be tightened to the specified torque (loose tightening will reduce the anti-loosening effect, while overly tight tightening may damage the anti-loosening structure, such as the nylon ring breaking). Some types require specific tools.

Disassembly:

- Ordinary nut: Easy to remove, with no additional resistance;

Anti-loosening nuts: Due to the anti-loosening structure, more torque may be required during disassembly (such as the friction force between the nylon insert and the thread). Some one-time anti-loosening nuts may be damaged after disassembly and cannot be reused.