Spiral Coil Binding FAQs

June 24, 2019
2528 Views

Spiral Coil Binding FAQs

1. What coil bind pitch do I need?

The most common binding pitch for spiral coils (by far) is 4:1 pitch, but some industry-specific customers use a 5:1. Click here more more details on coil bind pitch options.

2. What is the largest book a coil can bind?

If you're talking about sheet size, then the limit of size will depend on your machine. That being said, spiral coil binders are stocked in a 36" length (in addition to the standard 12" length) so you can bind a book up to 35" long.

If you're talking about book thickness, then the answer is about 440 sheets (20 lb bond copy paper), or a 1 ¾" thick stack using the largest coil available, a 50mm.

3. Why is the coil longer than my book?

Spiral coils are 1" longer than the intended binding edge length to allow for cutting and crimping-in each end. This leaves 1/2" on each side of your page; smaller extensions can be more difficult to handle. So, for example, standard coils are 12" long and intended for letter size paper that is 11" long.

4. How do I know what coil size I should get?

The most accurate way to determine the best coil size for your book is to lay all of your pages on a desk (including covers and any inserts) and measure the thickness of the stack, then add 1/8" to that. Make sure you are not pressing your pages down when you measure them; just allow them to lay loose. If you press down, you may end up with a coil size that is too small to allow your pages to freely turn.

Sample: My book is 5/16" thick + 1/8" = 7/16" should be the coil size. Since coils are measured in millimeters, not inches, you can use a conversion calculator like this to convert it. My 7/16" coil becomes 11.11 mm. Always round up to make page turning easier, which would mean I should use a 12 mm coil for my book.

Another way to determine the best size is by sheet count. Bear in mind, however, that sheet count is determined using all 20 lb bond copy paper, so if you are using thicker stock, have covers, tabs, or anything else, this may not be accurate. The following chart shows the sheet capacity, stack thickness, and recommended coil sizes for each:

SizeStack CapacitySheet Capacity*
6mm5/32" Thick Stack5-35 Sheets
7mm3/16" Thick Stack36-47 Sheets
8mm1/4" Thick Stack48-60 Sheets
9mm9/32" Thick Stack61-70 Sheets
10mm5/16" Thick Stack71-80 Sheets
11mm3/8" Thick Stack81-90 Sheets
12mm13/32" Thick Stack91-100 Sheets
13mm7/16" Thick Stack101-110 Sheets
14mm15/32" Thick Stack111-120 Sheets
15mm1/2" Thick Stack121-130 Sheets
16mm9/16" Thick Stack131-140 Sheets
18mm5/8" Thick Stack151-160 Sheets
20mm11/16" Thick Stack161-170 Sheets
22mm3/4" Thick Stack181-200 Sheets
25mm13/16" Thick Stack211-230 Sheets
28mm7/8" Thick Stack231-250 Sheets
30mm1" Thick Book251-270 Sheets
32mm1 116" Thick Stack271-290 Sheets
35mm1 ¼" Thick Stack291-320 Sheets
38mm1 ⅜" Thick Stack300-320 Sheets
40mm1 ½" Thick Stack321-350 Sheets
45mm1 916" Thick Stack351-390 Sheets
50mm1 ¾" Thick Stack391-440 Sheets

5. Is the coil size the outside or inside diameter?

Coil binder measurements are the inside diameter, or "ID".

6. Can I buy smaller packs?

Our coils are pre-packaged in packs of 100 or 50, depending on the size. We cannot break down packs to offer smaller quantities.

7. Can I buy assorted packs?

At this time we do not offer assorted color or assorted size packs. But if there is a demand for them, we may do this in the future, so let us know that you want us to carry assorted packs by emailing info@buy101.com.

8. Is coil binding better or worse than wire and comb?

All binding methods have their pros and cons. Coil, however, is pretty consistently wonderful-- which is why it is our best selling binding supply. And then, of course, there is user preference that plays a factor. This chart compares the three to help you decide if it is better or worse:

Binding TypeSpiral CoilsWiresCombs
Largest Book You Can Bind*1 ¾" Thick Stack
About 440 Sheets
(With a 50mm Coil)
1 ⅛" Thick Stack
About 260 Sheets
(With a 1 ¼" Wire)
1 ⅞" Thick Stack
About 425 Sheets**
(With a 2” Comb)
Part of the reason why coil bindings can hold more capacity, even compared to larger alternatives, is because they are a continuous loop of plastic. Wires are metal (which doesn’t have the same bounce-back) with loops that protrude into the holes, and combs have prongs or teeth that tuck under the spine. The continuous coil is stronger and can hold more pages, without worry about them falling out.
Damage when BentNoYesYes
Color ChoicesWhite, Black, Maroon, Red, Clear, Blue, Navy, Forest Green
+ many special-order colors, including (not limited to) purple, pink, yellow, orange, baby blue, teal, leaf green, gold, charcoal, brown, pearl white, & more
White, Black, Silver, Pewter, Blue, Navy, Gray, Gold, Green, RedWhite, Black, Clear, Gray, Blue, Navy, Maroon, Red, Green, Brown***, Matte Black***

9. Do you have more colors?

Yes, our production room has the equipment and tools to make several different special-order colors. You can see our most popular special-orders colors here, or request a different color by emailing us at info@buy101.com.

10. Is it possible to coil bind without a machine?

Having a spiral coil binding machine will give you the most variety of binding, as you will be able to punch any kind of paper stock you want, but yes, coil binding without a machine is possible (and easy)! Simply get pre-punched front covers, pre-punched backs, and pre-punched filler paper, along with the cutter/crimper pliers. Print your pages and, once all assembled, just manually roll the coil in through all the holes. Then crimp in the ends of the coil with the pliers. Note that some printers may not be able to run pre-punched pages, so check your user manual for compatibility.

11. How much do Spiral Binding Machines cost?

The price of a coil binding machine will depend on the volume it can handle as well as the integrated features. They start at about $175 and go up to several thousands of dollars. Our experts can help you find the best coil binding machine for your budget; just call us at (866)537-2244.


For more information or a quote, call us at (866) 537-2244 (866) 537-2244 or email info@buy101.com


Mallory Morsa, Binding101 Product Expert About the Author • Mallory Morsa has been a part of Binding101 since 2008 and has experience in several departments within the company. She began in customer service and sales where she honed in her skills to provide the customer with professional, fast, and accurate information. Shortly after, she was promoted to sales supervisor and also took on the role of product expert, training the team on new products. Throughout this time, she also wrote content for the site, as well as contributed stock photography and videography. As the team grew, she moved to an official position as the content specialist and social media manager. Her skills in these variety of areas give her the unique expertise to not just create content for the web, but to create content for you, the customer. She has a Bachelor's degree in business management and marketing, was on the Dean's List each year, and graduated Summa Cum Laude. In her free time, Mallory's favorite things to do include volunteering at the animal shelter by bottle feeding neonatal kittens, reading at the park, cooking plant-based meals, playing board games, and binge streaming TV shows with her 3 furbabies and family beside her.


Posted in: Binding 101