What is Wire-O Binding?

Double wire, twin loop, or Wire-O binding is a type of binding that is used for books that will be viewed or read in an office or home type environment. The binding involves the use of a C-shaped wire spine that is squeezed into a round shape using a wire closing device. Double wire binding allows books to have smooth crossover and is affordable in many colors. This binding is great for annual reports, owners’ manuals and software manuals. Wire bound books are made of individual sheets, each punched with a line of round or square holes on the binding edge.

Mold Changeover Free Double Loop Wire Binding Machine

This type of binding uses either a 3:1 pitch hole pattern with three holes per inch or a 2:1 pitch hole pattern with two holes per inch. The three to one hole pattern is used for smaller books that are up to 9/16″ in diameter while the 2:1 pattern is normally used for thicker books as the holes are slightly bigger to accommodate slightly thicker, stronger wire. Once punched, the back cover is then placed on to the front cover ready for the wire binding elements (double loop wire) to be inserted. The wire is then placed through the holes. The next step involves the binder holding the book by its pages and inserting the wire into a “closer” which is basically a vise that crimps the wire closed and into its round shape. The back page can then be turned back to its correct position, thus hiding the spine of the book.

Semi Auto Double Loop Wire Binding Machine

Wire binding is a popular commercial book binding method, and is known by various names, including double loop wire, double-o, ring wire, twin loop wire, wire comb, wire-o, wirebind and wiro. With this binding method, users insert their punched pages onto a C-shaped spine, and then use a wire closer to squeeze the spine until it is round. Documents that are bound with wire binding will open completely flat on a desk, and allow for 360 degree rotation of bound pages, without the side protrusion produced by spiral binding.

Automatic Double Loop Wire Punching and Binding Machine

Double Loop Wire

Hole patterns and pitches

There are three common hole patterns used in binding documents with double loop wire. Each hole pattern has specific sizes and applications where it is best suited.

3:1 pitch (3 holes per inch)

The 3:1 pitch hole pattern is most commonly used for binding small documents with double loop wire. Spines are available in sizes between 4.8 mm (3⁄16 in) and 14 mm (9⁄16 in) in diameter. The hole pattern can use either square or round holes.

2:1 pitch (2 holes per inch)

Although a 2:1 pitch hole pattern is most commonly used for binding larger documents, it can also be used for smaller books. It is most commonly found in sizes from 16 mm (5⁄8 in) to 32 mm (1+1⁄4 in). However, a couple of manufacturers make special small sizes, with diameters down to 6.4 mm (1⁄4 in).

19-loop wire

In the past, some comb binding machines would come with a wire closer. These machines were designed to be used with 19-loop wire, which uses the same pattern as for plastic comb binding. This hole pattern will have 19 longer rectangular holes that are on 14 mm (9⁄16 in) centers, for a total length of 280 mm (11 in). However, when Ibico was purchased, this type of supplies was discontinued. Today, 19-loop wire is commonly called Spiral-O Wire.

Wire binding equipment

In order to bind documents with double loop wire, a binding machine and a wire closer are required. Smaller organizations will often choose a small manual wire binding machine that offers a manual hole punch and a built-in wire closer. Medium-sized users will often choose a wire binding machine with an electric punch and built-in wire closer. The highest volume wire binding users such as binderies, print shops and in-plant printers will usually separate the punching and finishing stages of the binding process, in order to increase productivity. These users will often use a heavy-duty modular interchangeable die punch or an automated punching system, along with either a manual or an electric wire closing machine.

Automatic Double Loop Wire Forming Punching and Binding Machine