WHAT IS THE DIFFERENCE BETWEEN CHAIN GRADES AND HOW THEY’RE USED
Chain Grades One of the safety measures implemented was to place chain in Grades based on the ultimate breaking strength of that chain. This number is what we see today G30, G43, G70, G80 & G100 and the common chain grades . The number after each letter is N/mm2. For example, G80 means that the maximum stress on the chain at ultimate strength is 800 newtons per millimeter squared. Which Chain Grade Should Be Used for Which Type of Application? Alloy Chain Grade 80 or Grade 100 should be used for overhead lifting. Alloy chain shall be able to elongate a minimum of 20% before fracture. To ensure that the alloy chain consistently meets this requirement, ASTM requires the use of certain alloying elements in the manufacturing of the steel for alloy steel chain. These alloys can vary from company to company, but some key requirements are specified by ASTM. The alloy properties also improve the wear and tear that the chain will experience. Note that when chain is in use, no a...