Guides · size
How to measure a cable reel
Checked 9 November 2026 — To measure a cable reel, take four numbers with a tape: the flange diameter edge to edge across the face, the traverse between the flanges, the drum diameter, and the arbor hole at the centre. The flange is the number that matters most; it sets the reel's size, weight and truck.
From the reel desk · Checked 9 November 2026
Measuring, step by step
One. Measure the flange
Stretch the tape edge to edge across the face, through the centre. Round to the nearest inch. This is the reel's size.
Two. Measure the traverse
Measure inside, from one flange's inner face to the other, along the drum. Add both flange thicknesses for the overall width.
Three. Measure the drum
If you can see the drum, measure its diameter, or wrap the tape around it and divide by 3.14.
Four. Measure the arbor hole
Measure across the centre hole. Most wooden reels are 3⅛ inches; heavy steel reels 5¼ inches or more.
Five. Note the build and the tag
Nailed boards, plywood, steel or plastic. Photograph any tag or stencil; the reel number often gives all four sizes at once.
Why four numbers
Flange is what a reel is called by and what decides almost everything else: weight, vehicle, who wants it and whether it meets a take-back program's size rule (30 inches for AFL and Service Wire).
Traverse decides how tall the reel stands on end, which is the number a table buyer cares about. Two 36-inch reels in Southwire's tables stand about 19 and 32 inches high because their traverses differ.
Drum decides what the reel can carry again. A small drum bends cable sharply; stiff power cable needs a big one.
Arbor hole decides whether the reel fits a stand's shaft.
Tips for a quick, good measurement
- Measure the biggest reel in each group, not every reel. Group reels within a couple of inches of each other.
- Use the tag. Southwire's tags list the reel and its tare weight. Its stencils give the series and number (A-38, N-24); the packaging document turns that into dimensions.
- Photograph with the tape in shot. A photo of the tape across the flange settles any doubt.
- Check flange thickness at the rim if you hope a maker will take the reel: AFL wants at least 1½ inches.
- Count staves while you are there. AFL and Service Wire draw the line at about 75 percent intact.
Reels you cannot reach
In a tight yard, measure what you can see. The flange of the reel at the end of a row is enough to size the row if they match. Tall reels: measure the flange as a height from the ground to the top of the rim, standing beside it.
Rounding
Round to the nearest inch for the flange and traverse. Makers' sizes are not always round numbers: Southwire has reels at 23¾, 31 and 46 inches. The request form asks for a range, so an inch either way does not matter.
What to send
"Twelve reels, nailed, largest 48 inches across, 28 between the flanges, arbor 3⅛; four plywood around 24 inches" is a complete description. Add photos and you are done.
Reading the numbers
- Flange
- The diameter of the round end, edge to edge. The size a reel is known by.
- Traverse
- The inside width between the flanges, where cable winds. It sets how tall the reel stands on end.
- Drum
- The diameter of the barrel the cable winds onto. Stiff power cable needs a big drum.
- Arbor hole
- The centre hole for a shaft. 3⅛ in on most wooden reels; 5¼ in and up on heavy steel ones.
- Weight
- Empty, or tare, weight in pounds as the maker publishes it. A tag on the reel gives the same figure.
- Series letter
- Southwire codes the build: A and C nailed, N plywood or nailed, E and G plywood, S steel.
Reels you are likely to have
| Reel | Build | Flange | Traverse | Drum | Lb | Usually carries |
|---|---|---|---|---|---|---|
| C-5 | Nailed wood | 23 | 17 | 12 | 34 | Copper building wire, grounding |
| A-10 | Nailed wood | 30 | 22 | 16 | 66 | Service drop, bare aluminium |
| N-24 | Nailed wood | 36 | 28 | 14 | 83 | Insulated and multiplex cable |
| A-29 | Nailed wood | 42 | 28 | 21 | 154 | Overhead conductor, feeders |
| A-38 | Nailed wood | 48 | 28 | 24 | 212 | Aluminium and ACSR, large feeders |
| A-62 | Nailed wood | 60 | 28 | 28 | 397 | Utility conductor |
| A-76 | Nailed wood | 66 | 28 | 30 | 473 | Heavy conductor |
| S-120 | Steel, returnable | 84 | 36 | 42 | 895 | Transmission and medium voltage |
Other makers' reels differ by an inch or two. All flange sizes · How to measure
Sources
Each opened and read on 9 November 2026.
- Southwire, Reel Packaging Information (CableTech Support): reel series, wooden reel dimensions and weights, steel reel dimensions and charges, tag contents; cites NEMA WC26
- AFL, Wood Reel Recycling Program: nailed wood only, no plywood; flanges at least 1½ in thick and 30 in across; 75% of staves; full truckloads; mainly East Coast and Midwest