Seller guide · Published November 2026
Reel and spool sizes
A reel is described by three dimensions and one material, and those four facts decide how much cable it holds, how much it weighs empty and whether it can travel on the trailer you have.
Three numbers describe a reel
Flange diameter, inside traverse and drum diameter. Written together, as 60 × 28 × 28, they identify the reel precisely enough to find its capacity and its weight in a published table. The trade says drum; the same part is called the barrel, and both mean the core the cable is wound on.
Each number does a different job. The flange diameter governs how much cable can be wound and how tall the reel stands on its flange. The traverse is the inside width between the flanges, so it is the width of the wind and the width the reel occupies on a trailer. The drum sets how tightly the first layer bends, which is why large conductor and shielded cable go on larger drums.
Two smaller details belong in any description: the arbor hole, which is how the reel is lifted, chocked and tied, and the flange thickness, which is what separates a reel built for copper from one built for aluminum. Wood reels usually carry a 3 in. arbor; heavy steel reels run to 5 in. and more.
Packaging of wire and cable, including reel types and the four levels of protection a wind can be given, is standardized in NEMA WC 26. Returnable metal reels for aluminum conductor and ACSR follow Aluminum Association publication 53, and carry codes beginning RM or RMT.
The common sizes
Wood reels are built in a series of standard sizes rather than to order. The figures below are typical empty weights from a manufacturer’s reel table, and they are approximate: wood takes up and gives off moisture, so the same reel weighs more in August than in January.
| Flange × traverse × drum | Empty, about | Where it turns up |
|---|---|---|
| 30 × 22 × 16 | 65 lb | Small building wire, short lengths |
| 42 × 28 × 21 | 155 lb | THHN and XHHW, 500 ft to 1,000 ft |
| 48 × 28 × 24 | 210 lb | The common intermediate wood reel |
| 60 × 28 × 28 | 400 lb | Feeder, and small medium voltage |
| 68 × 38 × 36 | 540 lb | Heavier insulated cable, longer lengths |
| 84 × 36 × 42 | 900 lb | Steel returnable, bare overhead conductor |
| 96 × 60 × 42 | 1,100 lb | Steel returnable, long bare lengths |
| 118 × 85 × 78 | 3,700 lb | Large transmission lengths, flatbed only |
Tare weight is the number to check first on any reel being weighed. The stencil on the flange, where it survives, is the authority for that reel.
How much goes on
Capacity is geometry. The wind fills an annulus between the drum and the flange, so its volume is the difference between two circles multiplied by the traverse. Divide that by the volume of one foot of cable and apply a packing factor of about 0.85, because layers do not nest perfectly, and the answer is an upper bound on footage:
footage ≈ 0.85 × (flange² − drum²) × traverse ÷ (cable OD² × 12), all dimensions in inches.
| Cable OD | On a 60 × 28 × 28 | An OD of that size is roughly |
|---|---|---|
| 0.4 in. | about 32,000 ft | 14 AWG single conductor |
| 0.6 in. | about 14,000 ft | 1/0 AWG building wire |
| 0.8 in. | about 8,000 ft | 4/0 AWG building wire |
| 1.0 in. | about 5,100 ft | A 500 kcmil jacketed single conductor |
| 1.5 in. | about 2,300 ft | Three-conductor 15 kV, shielded |
| 2.0 in. | about 1,300 ft | Heavy multiconductor or large medium voltage |
The limit is usually weight, not volume. As an illustration, 5,100 ft of 1 in. cable at about 1.1 lb per ft is over 5,000 lb, more than a 400 lb nailed wood reel of that size is built to carry.
Returnable steel, plywood and process reels
Nailed wood is the default: two-ply flanges, steel tie rods, non-returnable, and the reel most surplus cable arrives on. Plywood reels are lighter and are used for building wire and lighter insulated product; they are also the ones whose flanges delaminate after a wet winter.
Returnable steel reels are a different proposition. They are heavy, they cost real money, they are tracked, and they are expected back. A steel reel in a surplus lot may still be the manufacturer’s property, which is a question to settle before the reel is described as part of the sale. Steel reels are also where the tare weight matters most, because the reel can be a fifth of the gross weight.
Process reels stay inside a plant and feed a machine; shipping reels travel. A process reel that appears in a surplus storehouse is often an odd size, heavier than it looks, and fitted with a hub rather than an arbor hole. Small wire and fibre arrive on plastic spools and plywood spools, which are measured the same way but rarely worth listing individually.
What fits on a trailer
A standard flatbed is 48 ft long with a 96 in. deck, inside a legal width of 102 in., and carries in the region of 45,000 lb of payload. Large reels go on their flanges, one tier, chocked on both sides and strapped over the flange rather than across the cable. Reels of 48 in. and under can travel on end, two high, banded to a skid.
A dry van has an interior width of about 98 in. and a door about 110 in. high. A 96 in. reel will pass through that door standing on its flange with inches to spare on each side, and a 118 in. reel will not go in at all. Height is the other limit: a 96 in. reel on a 48 in. deck sits at 144 in., inside the usual 13 ft 6 in. limit, while a 118 in. reel on the same deck needs a step deck or a permit.
Weight per reel decides the rest. A 5,000 lb reel on a van floor is a point load and needs spread under it; the same reel on a flatbed is ordinary. The arbor is how it is lifted and how it is tied, so a bent arbor or a split flange means the reel has to be rewound before it can travel at all.
Questions on this guide
Does the flange diameter include the cable?
No. It is the reel. The cable sits inside the flanges, usually a little below the rim, so the wound diameter is smaller than the flange.
Why does the same reel size hold different lengths?
Because capacity falls with the square of the cable diameter. A small change in outside diameter moves the footage a long way.
Can a steel reel be kept?
Only if the releasing party says it is included and free of a return obligation. Otherwise the reel goes back and the cable is rewound or shipped on wood.
Send the reel list, not the weight ticket
Construction, footage and condition decide a review. Photographs of tags and cut ends answer the rest.