Socket Systems manufactures the metal joinery system called Lumber Link. This 3-16″ steel “socket”, joins 6″x 6″ rough-cut timbers or wood members, to create a clear span building frame. The standard Lumber Link kit can create a clear span area up to 30 feet wide. Extensions of 15 feet on each side will make the building 60 feet wide. The 6″ x8″ Hercules fixture can build clear spans up to 60 ft. wide with certain requirements. We also supply steel rafters with pre-welded purlin clips in a …shed plans