Chains are fundamental tools in various industries, prized for their strength and reliability. From lifting heavy loads to securing cargo during transport, selecting the right type of chain can significantly enhance safety and efficiency. This guide will delve into the nuances of chain grades, the types available, and their respective working load limits (WLL), providing a comprehensive understanding without referencing specific brands.

 

top steel chain

What is a Chain Grade?

A chain grade indicates the strength and durability of a chain, determined by its material composition and manufacturing process. These grades are essential for selecting the appropriate chain for specific tasks to ensure safety and effectiveness. The grading system bases itself on the ultimate breaking strength of the chain, measured in newtons per square millimeter.

Types of Chain Grades

Various chain grades categorize by numbers that reflect their maximum strength and application suitability. The most common grades include:

  • Grade 30 (G30): Known as the general-purpose chain, it’s made from carbon steel and suitable for light to medium duty applications where high strength is not critical.
  • Grade 43 (G43): Often used in agriculture and automotive applications, this high-test chain offers greater tensile strength than G30.
  • Grade 70 (G70): This heat-treated carbon steel chain is designed for binding and tie downs but is not recommended for overhead lifting due to its limited elongation properties.
  • Grade 80 (G80): A heat-treated alloy steel chain typically used for lifting and rigging applications. It provides a good balance of strength and durability.
  • Grade 100 (G100) and Grade 120 (G120): These are high-performance chains with even greater strength, used for heavy-duty lifting applications. Grade 120, recognized by its square links, offers the highest strength-to-weight ratio.

Grade 43 Hot Dipped Galvanized Half Drum

Working Load Limit (WLL) of Chain

The WLL is a crucial factor in selecting the right chain for specific tasks. It defines the maximum load that the chain can safely support under normal conditions. Industry standards typically set the WLL by considering the chain grade, the type of material used, and the safety factor. It is essential to adhere to the WLL to prevent accidents and ensure the longevity of the chain.

  • Grade 30: Supports light loads; suitable for utility tasks.
  • Grade 43 and Grade 70: Ideal for securing loads during transportation; Grade 70 is especially popular in the trucking industry due to its robustness.
  • Grade 80 and above: Best for overhead lifting and critical applications where safety is paramount.

Choosing the Right Chain Grade

Selecting the correct chain grade depends on the intended use, load weight, and environmental conditions. For overhead lifting, recommend alloy chains such as Grade 80 or higher due to their strength and ability to handle dynamic stresses. In contrast, lower grades like G30 or G43 are sufficient for lighter loads and less critical tasks.

It is also crucial to consider the specific characteristics of each chain grade, such as elongation, wear resistance, and suitability for exposure to certain environments, to ensure optimal performance and safety.

Understanding chain grades and their respective working load limits is essential for selecting the right chain for your needs. By considering the type of load, the conditions under which the chain will be used, and adhering to safety standards, you can effectively enhance operational safety and efficiency.

 

PDFExploring Chain Grades: Understanding Types, Applications