Our plastic screwposts are available in either black, white or clear and are packaged 100 sets (100 posts, 100 caps each). Plastic screw posts are available in lengths of 1/8" to 1".
The Screw Post length or total height of the rear barrel/post portion are the minimum binding thickness of the book. For instance a 1/4" screwpost when tightened 100% will accomodate a 1/4" thick book, or slightly larger if not tightened all the way. The overall/total length of a post with the screw installed is approximately 1/8" longer than the length that is listed.
The binding posts on these items are 1/4" in diameter, which fits comfortably in a standard 5/16" punched or drilled hole. Post and screw heads are 3/8" diameter and 1/8" thick. The heads can be tightened & secured using a standard 'flat blade' screwdriver for all sizes except 1/8" (these just snap together). Every size can be snapped together as well since the barrels are self-tapping & are not pre-threaded.