Charles Leonard - Post Binder Aluminum Screw Posts, 3/16" Diameter, 1/2" Long, 100/Box - Sold As 1 BoxTo bind catalog covers, price lists, sample books. Posts are 3/16" dia. with 3/8" heads. Work with most screw post binders. Length: 1/2 in; Capacity (text): N/A; Material(s): Aluminum; Post Diameter: 3/16 in.Binds catalog covers, price lists and sample books.Works with most screw post binders.