Understanding Chain Grades

Carbon and alloy steel chain

Welded chain falls into two categories:

1. Carbon steel chain (most commonly used for tie down and container securement purposes and not recommended for overhead lifting)

2. Alloy steel chain (unlike carbon chain, all graded alloy steel chain is recommended for overhead lifting)

Grade is important when it comes to the difference between carbon and alloy chain. The biggest difference between Grades of chain is that carbon steel chain (Grade 30, 43, and 70) is not recommended for overhead lifting, while alloy steel chain (Grade 80, 100, and 120) is recommended for use in sling assemblies and overhead lifting applications.

(However, chain slings made from alloy steel are not suitable for use in acidic environments as this can cause hydrogen embrittlement.)

Manufacturers are now developing Grade 140 and 160 for the Australian market in other industries that will soon find their way into the lifting industry. These chain systems are being developed within Europe but the manufacturers are specifically targeting the Australian market.

Australia has already recognised the value of using Grade 100 for overhead lifting with the revision of standards related to chain slings for lifting purposes. The Australian Standards: ‘AS 3775.1: 2014 Chain Slings for Lifting Purposes – Part 1 – Product Specification’, and ‘AS 3775.2: 2014 Chain Slings for Lifting Purposes – Part 2 – Care & Use’ have both been extended to include Grade 100 systems as well as Grade T(80) systems and similarly the scope within AS 3776: 2015 Lifting Components for Grade T(80) has been extended to include Grade V(100).

In Australian Standard ‘Chain slings for lifting purposes—Grade T(80) and V(100)’ the quality grading system provides for the variations in mechanical properties of the finished product. Each grade is identified by a letter in the series T(80) or V(100) which allows for positive identification and easy selection.

Note that several different Grades of material are used for lifting equipment, which results in slings, crane hooks, shackles, and other lifting components varying considerably in size for a given capacity. Care shall be taken to ensure the compatibility of the ancillary equipment used to sling the load, both in size and capacity. An intermediate link or shackle may be required to allow for a suitable compatibility between components.