#22 - 9/16" Threaded Nail Back button can be used on it's own for pounding into wood but for a more secure installation they are commonly used with a Spring Back Washer (sold separately). This washer ensures a positive plascement of the button even in wood, it prevents pulling out as the wood ages and movement of the button occurs, loosening the nail back.
Available in 2 lengths.
Sold each.
.