Narrow slit strip can be packaged two ways: as pancake coils or on oscillate wound spools. Both hold the same strip. The difference is how it’s wound, and that changes how much footage comes in each package.
Pancake coils
A pancake coil is strip wound flat on top of itself around a cardboard core, the way a roll of tape is wound. Each wrap sits directly on the one below it, so the coil is only as tall as the strip is wide, and it grows outward as more strip is wound on.
A pancake coil’s size is described by its I.D. (set by the core it’s wound on) and its O.D. (set by how much strip is wound on). For the core sizes we use, the core typical for each thickness and our maximum O.D., see What coil I.D., O.D. and core size can I order?
Narrow pancake coils are often stacked for shipping, with spacers between them and strapping to hold the stack together, as in the photo above.
Oscillate wound spools
Oscillate winding, also called traverse winding, moves the strip back and forth across the width of a spool as it winds, laying wrap after wrap side by side, the way thread is wound on a bobbin. Instead of one narrow spiral, the spool builds up many rows of strip across its full winding width.
Because the strip fills the width of the spool, one spool holds far more footage than a pancake coil of the same strip. That means fewer package changes and longer, uninterrupted production runs. To make one continuous length, strip lengths are joined with laser welds.
Side by side
| Pancake coil | Oscillate wound spool | |
|---|---|---|
| How it’s wound | Flat spiral, each wrap on top of the last | Traversed back and forth across the spool width |
| Wound on | Cardboard core | Spool |
| Footage per package | Limited by coil O.D. | Far more footage per package |
| Continuous length | One length per coil | Lengths joined with laser welds |
| Size described by | I.D. and O.D. | Spool size (I.D., O.D. and traverse width) |
Our spool sizes
We oscillate wind onto spools in two sizes. Both sizes take the same range of strip.
| Small spool | Large spool | |
|---|---|---|
| Strip thickness | .002″ – .020″ (0.05 – 0.51 mm) | .002″ – .020″ (0.05 – 0.51 mm) |
| Strip width | .125″ – .785″ (3.18 – 19.94 mm) | .125″ – .785″ (3.18 – 19.94 mm) |
| Inside diameter (I.D.) | 1½″ (38.1 mm) | 5″ (127 mm) |
| Outside diameter (O.D.) | 11¾″ (298.5 mm) | 22″ (558.8 mm) |
| Traverse (winding) width | 7″ (177.8 mm) | 11″ (279.4 mm) |
| Maximum weight | 125 lb (56.7 kg) | 500 lb (226.8 kg) |
The I.D. is the bore through the center of the spool, which mounts on your payoff. The traverse width is the width of the winding area between the spool flanges.
Specifying your packaging
Your equipment usually decides the packaging. A spool has to fit the payoff that unwinds it, and a pancake coil has to fit your mandrel’s I.D. and your maximum O.D. When you request a quote, tell us which you need — pancake coils with the coil I.D. and maximum O.D. or weight, or oscillate wound spools with the spool size — on your request for quote.
This article is educational information only. Packaging and spool availability are confirmed with each quote.