Master links are used as the top link (aka "head" link) for chain slings, wire rope assemblies and other rigging assemblies. These master links from Crosby are made from forged, Grade 100 alloy steel that is Quenched and Tempered (the X7 size is welded). Each link is proof-tested as part of the manufacturing process and certificates are available at no additional charge. The flat spot on the link is engineered into the design, and it allows for the use of S-1325A Couplers
. Safety factor of 4:1.