Double wires are continuous metal wires that form pairs of loops that are joined together to form a binding element. These rings resemble the letter C when opened and viewed from the end. After the page is loaded on the element, the line is enclosed in a circle. Iron Double Binding Coil gives your book a very professional look, allows pages to turn easily, and leaves the book completely flat when opened. Pages remain aligned when opened, so spreadsheets, charts, graphs, and illustrations that extend into the middle of the book will stay aligned correctly. Pages can also wrap around to the back of the book, which marks your position in the book and gives it half the footprint while remaining flat. Multiple styles are available, and multiple materials can be combined in the same book. The standard double line binding edge is 11 inches long and uses 32 rings or holes or 21 depending on the spacing. Double lines also give you the flexibility of multi-spaced binding. Only parts of the book are bound. The length and width of the binding edge can also be customized for your specific project.

The double-loop helix is ​​produced "open" for insertion into appropriately sized pre-punched holes. Once inserted into the correct holes, they just need to be crimped with wire closers. A 3 to 1 (3:1) pitch is used for books up to about 1/2 inch thick, and a 2 to 1 (2:1) line can be used for books up to about 1-1/8 inches thick; however, 2 to1 (2 :1) Can also be manufactured from 1/4" to 9/16" upon request.
Factory Plastic Binding Comb 21/19 Rings for Loose-leaf notebook-Plastic Binding Combs/Rings