16mm Spiral Binding Coils

Plastic spiral coil is well suited to documents that need to lie flat or fold back during use. Its continuous shape supports the punched edge while allowing the covers and sheets to rotate around the spine. Durability still depends on correct sizing and finishing. A coil that is too small places pressure on the holes, while one that is too large allows unnecessary movement and can make the document feel unstable. Cover material also matters because thin paper covers may wear sooner than poly or heavier stock. For manuals used frequently, assemble the full document and observe how it turns in the intended position. Smooth movement with no visible strain is a better indicator of long term performance than sheet count alone.

The machine must punch the same pitch as the coil, provide enough punching width for the document, and handle the chosen cover material within its rated capacity. These 16mm coils use a 4:1 pattern, so the equipment must create four holes per inch. The range of coil binding machines includes manual and electric punching options for different production volumes. An integrated inserter can speed threading, but separate insertion equipment may suit an existing punch. Also consider disengageable pins for unusual sheet lengths and an open throat for longer documents. Heavy covers should often be punched separately. A sample run confirms hole alignment, edge margin, and the ease of threading before full production.

No. Diameter controls document thickness, while coil length follows the punched edge. A 12 inch coil is commonly used for an 11 inch binding edge because the extra material can be trimmed and crimped. A shorter document may need the coil cut down, and a longer edge needs a longer supply that reaches every hole. Do not select length from the document width unless that is the edge being punched. Lay the coil beside a punched sample and confirm that it extends slightly beyond both end holes. This small allowance is needed for secure crimps. Excessive overhang creates waste and untidy ends, while insufficient length can leave holes unsupported or make proper finishing impossible.

Thread the coil through every hole, trim the excess, and form a complete crimp at both ends. The crimp should flatten the final loop and bend it toward the document edge so it cannot pass back through the last hole. Handheld and electric coil crimpers are made for this finishing step and can support occasional work or repeated production. Leave about half to one and a half loops beyond the final hole before cutting. A very short end may not provide enough material for a secure stop, while a long end can catch during handling. Test the finished document by rotating the coil gently in both directions. Properly formed ends should resist backing out without interfering with smooth sheet turning.