Create sturdy, concealed bed rail connections with ease. This ingenious system incorporates threaded rod, threaded inserts and unique slotted washers to produce a strong and secure metal-to-metal connection. Hardware is not visible from the exterior of the bed frame, eliminating the need for bed bolt covers. To install, drill a 35mm (1-3/8") flat-bottom hole and perpendicular 5/8" through-hole in the bed rail, and a 17/32" hole in the bed post to house the threaded insert. TIP: To speed installation and ensure accurate drilling, use the Rockler JIG-IT Drill Guide and 35mm Long Shank Forstner Bit for the bed rail boring. The JIG-IT sets up quickly to produce accurately placed, flat-bottom holes in the exact depth required.