DIN980 All-Metal Lock Nuts | Types, Mechanical Properties & Installation Guide

Comprehensive Guide to DIN980 All-Metal Lock Nuts: Types, Principles, and Mechanical Properties

Metal lock nuts play a crucial role in industrial assembly, automotive applications, and heavy machinery by preventing loosening under vibration and dynamic loads. Common types include metal flange lock nuts, all-metal prevailing torque hex nuts, square nuts, ball nuts, flange nuts, hexagon nuts with tapered elastic washers, wheel lock nuts, hexagonal flange jam nuts, round weld nuts, cap nuts, wing (butterfly) nuts, thin castle nuts, plate welding nuts, adjusting nuts, knurled set nuts, 12-spline flange nuts, and gold-plated spring band hex lock nuts.

This article provides a detailed overview of DIN980 all-metal locking nuts, including their locking mechanisms, installation methods, and mechanical performance, making it a valuable reference for engineers, procurement specialists, and manufacturing professionals.

 1. Locking Mechanisms of All-Metal Lock Nuts

All-metal locking nuts, also called all-metal self-locking nuts, are designed to maintain joint integrity without additional nylon inserts. Their primary locking forms are divided into two main types:

1. Thread Deformation Locking (DIN980-V Type)
        This type achieves anti-loosening through controlled deformation of the      nut threads. Common standard forms include:

• End-face three-point type

• Oval type

• Side extrusion type

b. Nuts embedded metal locking piece, by the locking ring to play a loosening role, such nuts are called 980-M type, standard forms are as follows:

1. Embedded Metal Sheet Locking (DIN980-M Type)
        This type features a heat-treated metal sheet embedded inside the nut. The      sheet slightly reduces the effective inner diameter, gripping the bolt      threads tightly during installation to prevent vibration-induced      loosening.

2. Working Principles

• DIN980-V Thread Deformation
       The threads are deformed by approximately three teeth during      manufacturing. The nut’s internal thread diameter becomes slightly smaller      than the bolt’s outer thread diameter, creating increased friction during      tightening. This friction effectively prevents loosening under dynamic      loads.

• DIN980-M Embedded Metal Sheet
       The embedded metal sheet engages with the bolt threads when tightened,      providing reliable anti-vibration and anti-loosening performance,      especially suitable for high-vibration applications.

 3. Installation Guidelines

• Tools Required: All-metal lock nuts      must be installed using appropriate tools, such as ratchets or torque      wrenches.

• Lubrication Recommendations: For      stainless steel lock nuts, pre-lubrication is advised to reduce      installation torque and prevent galling during rapid assembly.

• Reusability: Lock nuts can be      reused; however, repeated disassembly and reinstallation (beyond 3–4      times) significantly reduce locking torque. For optimal performance, avoid      frequent reuse in critical applications.

 4. Mechanical Properties

All-metal locking nuts maintain mechanical properties similar to standard hex nuts:

• Carbon Steel Grades: 8, 10, 12

• Stainless Steel Grades: 70, 80

Standards Compliance:

• Carbon steel nuts should meet ISO 898-1 mechanical property      requirements for load and hardness.

• Stainless steel nuts are evaluated based on load-holding      performance equivalent to carbon steel nuts and do not require specific      hardness testing.

• Locking performance must comply with ISO 2320, which defines      torque retention requirements across five tightening cycles—an essential      standard for high-performance anti-loosening nuts. Ordinary nuts do not      have this requirement.

 5. Applications and Recommendations

Industries:

• Automotive manufacturing

• Heavy machinery and equipment

• Industrial assembly lines

• High-vibration environments

Best Practices:

• Always follow torque specifications for DIN980 lock nuts to      ensure optimal locking performance.

• Pre-lubricate stainless steel nuts for smoother installation.

• Limit repeated use to maintain consistent torque retention.

 Key Takeaways for Engineers and Procurement Teams

• DIN980 all-metal lock nuts offer reliable anti-loosening      performance under vibration.

• Selection should consider thread type (V vs. M), material      (carbon vs. stainless steel), and application environment.

• Compliance with ISO 898-1 and ISO 2320 ensures      mechanical reliability and safety in industrial and automotive assemblies.

By understanding the types, principles, and mechanical properties of DIN980 all-metal lock nuts, engineers can make informed decisions for high-performance fastening solutions in demanding applications.