Lock Nut

Lock Nut — Product Introduction

The tightening nut (GB/T 805) is an anti-loosening nut that achieves locking through the elastic deformation of spring steel, typically used as an anti-loosening accessory together with standard hex nuts. Its structure features an open or crimped form; during installation it relies on its own elasticity to grip the bolt threads and generates additional friction against the face of the standard nut, thereby effectively preventing the nut from loosening under vibration, shock, or alternating loads. This product is typically made from high-quality spring steel such as 65Mn. After quenching and tempering, hardness is generally controlled within HRC 42–50, providing good elasticity, wear resistance, and fatigue resistance. Common surface treatments include blackening, zinc plating, and phosphating to improve corrosion resistance. Tightening nuts cover a wide range of metric and inch thread sizes and are widely used in various threaded connection applications that require reliable anti-loosening.

I. Product Features

• Elastic locking structure: Open or crimped design — after installation, it uses the elastic recovery force of spring steel to grip the threads and achieve effective locking.
• Used with standard nuts: Typically installed as an anti-loosening accessory on the outside of a standard nut, without changing the original connection structure.
• Good elasticity and hardness: Made from spring steel with heat treatment, hardness is generally HRC 42–50, balancing locking force and durability.
• Multiple specifications available: Metric, inch, and other thread specifications are offered to match bolts of different diameters.
• Diverse surface treatments: Blackening, zinc plating, phosphating, and other treatments are available to meet anti-corrosion requirements in different environments.
• Compact structure: Small size and light weight, suitable for space-constrained assembly applications.

II. Product Advantages

• Significant anti-loosening effect: Relies on the dual action of elastic gripping force and face friction, markedly improving the vibration resistance and anti-loosening capability of the threaded connection.
• Easy installation: Simply screw it on and tighten it above the standard nut — no special tools or changes to the original assembly process are needed.
• Economical cost: Simple structure and mature manufacturing at a low price, making it a cost-effective anti-loosening accessory.
• High versatility: Compatible with standard hex nuts, bolts, and the like — wide range of applications.
• Good reliability: Under normal vibration and shock conditions, the anti-loosening effect is stable and meets the requirements of most mechanical equipment.
• Easy maintenance: Detachable and reusable, convenient for equipment inspection and component replacement.

III. Application Scope

• Mechanical equipment: Anti-loosening of threaded connections in machine tools, reducers, pumps, fans, and other equipment.
• Automotive industry: Anti-loosening connections in chassis, engine accessories, and body vibration areas.
• Home appliances: Areas in air conditioners, washing machines, refrigerators, and other products that require prevention of screw or nut loosening.
• Electronic equipment: Anti-loosening of bolt connections in cabinets, control boxes, instruments, and measuring equipment.
• Architectural hardware: Fastening points in metal structures, brackets, and guardrails that require anti-loosening.
• Rail transit: Connection points with high vibration such as interior vehicle equipment, electrical enclosures, and rail accessories.
• Other general industries: Wherever a low-cost, simple, and reliable anti-loosening threaded connection is needed, tightening nuts can be used.