How do I bind a document using spiral coil binding?

Spiral coil binding — also called plastic coil or color coil — produces durable, flexible documents that open completely flat, rotate a full 360 degrees, and hold up to heavy daily use better than most other binding methods. It is the method of choice for textbooks, workbooks, cookbooks, field guides, and any document that will be opened flat on a desk or used repeatedly in hand. This guide covers the complete coil binding process from pitch selection through threading, crimping, and final inspection.

Not sure whether coil binding is the right system for your application? See our overview on what you should know about spiral coil binding before selecting supplies.

What Is Spiral Coil Binding?

Spiral coil binding uses a continuous helical coil made of PVC plastic. The coil threads through a row of round holes punched along the binding edge of a document — entering through the front cover at one end and exiting through the back cover at the other. Once fully threaded, both ends of the coil are crimped using coil crimping pliers, permanently preventing the coil from unwinding backward out of the document during use. Crimping both ends is a non-negotiable finishing step on every coil-bound document — a document with one or both ends left uncrimped will gradually unwind with normal page-turning use, eventually releasing pages from the binding entirely. The crimp takes under five seconds per end and requires no machine, only a pair of purpose-designed coil crimping pliers. The finished document opens completely flat to 360 degrees and can rotate so both sides of each page are accessible simultaneously.

Coil is available in dozens of colors and in diameters from 6 mm (approximately 25 pages) to 50 mm (approximately 450 pages). It comes in two standard pitches: 4:1 (4 holes per inch) and 5:1 (5 holes per inch). These pitches are not interchangeable — the coil pitch must match your punch machine's punch die configuration. For pitch selection help, see our guide on what coil binding pitch you need.

Supplies You Need for Coil Binding

Required Equipment

A coil punch machine (4:1 or 5:1 pitch), spiral coil spines in the matching pitch and correct diameter for your document, coil crimping pliers, and front and back covers. For a complete supply checklist with recommendations on cover stock and coil length selection, see our article on what coil binding supplies you should have.

Optional — Electric Coil Inserter

An electric coil inserter automates the threading step, reducing insertion time from 1–2 minutes per document (by hand) to under 30 seconds. For volumes above 15–20 documents per day, an inserter is strongly recommended. See our complete inserter buying guide on what to look for in a spiral coil inserter for evaluation criteria.

Coil Length

Coil should extend approximately 1/4 to 1/2 inch beyond each end of the document spine — this extra length provides material for the crimp on each end. Standard coil lengths are 12 inches for letter-size documents and 14 inches for legal-size documents.

How to Bind a Document Using Spiral Coil — Step-by-Step

Step 1 — Select Coil Pitch and Diameter

Confirm your machine's punch pitch (4:1 or 5:1) and purchase matching coil. Select diameter based on your document's page count using the quick reference table below. A coil that is too small makes threading difficult; one too large leaves the document loose inside the coil.

Step 2 — Punch the Document

Assemble your document in final order with covers. Set the machine's paper stop to your paper's spine length. Punch in consistent batches within the machine's rated capacity per stroke. Overpunching produces ragged holes that weaken the paper and increase the risk of tearing during use. For guidance on using different document sizes with a coil machine, see our article on easier ways to bind coil documents.

Step 3 — Thread the Coil

Insert the coil tip into the first hole at one end of the document. Rotate the coil in the direction of the helix while feeding it through successive holes — maintaining even tension so the coil advances smoothly through each hole without forcing or skipping. Threading by hand takes 1–2 minutes per document; an electric inserter reduces this to under 30 seconds.

Step 4 — Crimp Both Ends

Once the coil is fully threaded and extends slightly beyond both ends of the document, use coil crimping pliers to flatten and close the last 1–2 loops at each end. Squeeze the pliers firmly — the loop should close and flatten, preventing the coil from spinning free. Repeat at the other end. Test both ends by pulling the coil — neither should be able to pull out of the document under firm pressure.

Step 5 — Final Inspection

Open the finished document and verify it lies completely flat. Pages should open cleanly with no catching on the coil. Both crimped ends should be flush against the document edges with no sharp protrusions. The document should rotate a full 360 degrees for double-sided use.

Quick Reference — Coil Diameter by Page Count

Troubleshooting

Frequently Asked Questions

How do I know which coil pitch to buy?
Check your punch machine's specification label or manual for its pitch — 4:1 or 5:1. Purchase coil in the matching pitch only. Mismatched pitch cannot be corrected in use. See our full pitch guide on what coil binding pitch you need.

Can I reuse a spiral coil after removing it from a document?
A coil can technically be re-threaded after removal but the crimped ends need reshaping and the coil may have lost some original tension. For professional-quality results, use new coil for each binding job.

Do I need a coil inserter?
For fewer than 15 documents per day, hand insertion is practical. For higher volumes, an inserter significantly reduces labor time. See our buying guide on what to look for in a spiral coil inserter for evaluation criteria.

What is the maximum document length I can coil bind?
Standard coil lengths accommodate letter (11 inches) and legal (14 inches) spine lengths. Longer coil for tabloid or ledger paper (up to 17 inches) is available as a specialty product.

How does coil binding compare to wire-O binding?
Both use a spiral spine, but coil uses a single continuous helix while wire-O uses paired loops at each hole. Coil is lighter, more colorful, and opens to a slightly wider angle; wire-O has a more formal appearance preferred for presentations and calendars. See our overview of the most common binding methods for a full comparison.