You have seen them used on commercial furniture for years. You probably have built some “Ready to Assemble” furniture that used these fasteners. They are easy to use, easy to design around, and have incredible holding power, especially in joints that span end grain. End grain, of course, creates some real problems for mechanical fastening systems. The grain just doesn’t hold a fastener as well as face grain. That’s why the RTA furniture industry has adopted this fastener so completely. It does not depend on the notoriously poor fastener holding power of end grain for its joint strength, and it is virtually impossible to assemble the joint incorrectly, an important advantage in the RTA market.
Construction of the joint is easy. Drill a 1/4" dia hole into the end grain as clearance for the connector screw. Then drill an intersecting 13/32" diameter hole for the 3/8"dia barrel nut. Drop in the barrel nut, align it to the connector screw hole, slip in the connector screw, and you’re done. Imported.