How is Chain Grade Measured?

Transport chains are high strength chains used in applications where much strength is needed yet the task served is rather straightforward. Sometimes referred to as grade 70 binder chain, cargo chain, high-tensile chain, or trucking chain, this heavy-duty chain is designed for tie down applications. Grade 70 chain is never to be used for overhead lifting.

How is Chain Grade Measured?

Chain grades are specified by the NACM (National Association of Chain Manufacturers) and the ASTM (American Society for Testing and Materials) standards that define the dimensional, mechanical, and compositional requirements that determine the proof of the steel, minimum breaking force required, elongation, etc. The combination of these measures determines the working load limit that each heavy duty chain can handle before risk of breakage. These factors are tested in a laboratory setting to ensure chain load capacity.

Grade 43 chain, also known as High Test Chain, is a mid-grade cargo chain with a working load limit of 5,400 lbs for 1/2″ chain. Grade 30 Chain，also called proof coil chain，is a light to medium duty chain，Grade 70, referred to as Transport Chain, is top level of heavy chain with a working load limit as high as 11,300 lbs of cargo for 1/2″ chain. Chain suppliers are required to clearly mark 5/16” and 3/8” chain links with their grade within 1 foot intervals along the truck chains, and within 3 foot intervals for ½” chain. This is to ensure easy identification and promote safety. It is very important to use the right heavy duty chain for the load you are transporting and these rules are D.O.T. enforced