The thread on Ball End Fittings made from 316 grade stainless steel are available in both 1/4-28 and 5/16-24 thread configurations. Both options are designed to be used in conjunction with the Threaded Termination Studs and Threaded Termination Stud Turnbuckle Assemblies as well as our Surface and Back Mounting Ball and Socket System. Note: Hole in post to be 1/2″ diameter.