13mm Spiral Binding Coils

No. Sheet capacity is normally based on plain 20 lb paper, so thicker paper, laminated inserts, tab dividers, and sturdy covers reduce the number of sheets that fit comfortably. The physical thickness of the assembled document matters more than the printed sheet count. Measure the stack at the punched edge because coatings and cover stock can create more bulk there than expected. The finished book should turn easily and fold back without pulling against the holes. When the stack sits close to the practical limit, moving to the next diameter is usually better than compressing the document into a tight coil. Test with the real materials rather than a substitute stack, since even a modest paper weight change can affect the fit.

The coil pitch must match the holes made by the punch. These 13mm supplies use a 4:1 pattern, meaning four holes per inch along the binding edge. A coil with this spacing will not thread correctly through a 5:1 pattern, even when the diameter is otherwise suitable. A 4:1 punch should be paired with 4:1 spiral coil binding supplies so the turns align with the punched document. When the machine label or manual is unavailable, make a test punch and count roughly four holes across one inch. Confirm pitch before choosing color or diameter, since pitch determines basic compatibility. A mismatch cannot be corrected by stretching the coil or forcing it through the holes.

Coil length should follow the length of the punched binding edge, not the document’s overall dimensions. Standard 12 inch coils are commonly used for an 11 inch binding edge because the small excess can be trimmed before both ends are crimped. Shorter documents can use a cut coil, while longer binding edges require a longer supply that covers every punched hole. Leave enough material beyond the first and last hole to form secure crimps, but avoid leaving long ends that may snag during handling. Test the coil against a punched sample before producing the full run. The correct length should pass through all holes, allow clean trimming, and leave both finished ends tucked close to the document edge.

After the coil is threaded through the document, both ends must be cut and crimped so the coil cannot rotate back out of the holes. A proper crimp flattens and bends the final loop toward the document, creating a stop at each end. Crimpers and insertion aids are grouped with spiral coil accessories for this final operation and for smoother work when production volume increases. Leave roughly half to one and a half loops beyond the final hole before trimming and crimping. Too little material can create a weak stop, while too much leaves an untidy end. Test both crimps by gently trying to rotate the coil backward. Secure ends should resist movement and remain close to the binding edge.