How to measure a cable reel

Step by step

1. Flange diameter. Stand the reel on edge. Run the tape across the face through the centre hole, rim to rim. Round to the nearest inch.
2. Drum diameter. Measure across the drum where it meets the flange, through the centre. If you can only reach one side, measure from the drum surface to the flange rim and subtract twice that from the flange diameter.
3. Traverse. Measure the inside gap between the two flanges, across the drum. Measure at two points; flanges sometimes lean.
4. Arbor hole. Measure the centre hole. Note whether it has a steel ring or plate.

What else to note

• Overall width outside the flanges, which matters for trucks and payoff stands.
• Flange thickness, a hint at build and weight.
• Whether there are drive holes, and their distance from the centre.
• Build: nailed, bolted, plywood, plastic or steel.
• Any stencils, tags or reel numbers.

Measuring a stack quickly

In a yard of mixed reels, measure only flanges at first and sort into size groups. Then measure one reel in each group in full. That is enough for a quote: "fourteen 36s, about 18-inch drums; eight 48s, about 24-inch drums". Photograph a tape across one flange in each group so the numbers can be checked.

Common mistakes

• Measuring the flange across a chord instead of through the centre, which reads short.
• Measuring traverse outside the flanges instead of inside.
• Measuring the drum at a spot where staves are missing.
• Reading a 48-inch reel as 50 because of a bulging board.

Using the numbers

Flange and traverse decide whether a reel fits a stand or a trailer. Drum and traverse, with the cable diameter, decide how much cable fits: put them into the capacity calculator. Flange and build are what a buyer needs to quote.

Converting to millimetres

Some buyers, rewinders and equipment manuals quote metric dimensions. Multiply inches by 25.4: a 36-inch flange is about 914 mm, an 18-inch drum about 457 mm, and a 3-inch arbor about 76 mm. Round sensibly; nobody measures a weathered wooden flange to the millimetre, and a quote never depends on it.

Keep the original inch figures alongside, because most North American buyers and stands still work in inches.

Safety while measuring

• Never stand in front of a reel on edge while someone else removes its chocks.
• Don't climb on reels to reach across a big flange; use a long tape from the ground.
• Watch for protruding nails at the flange rim and between staves.
• Wear gloves around wire-rope reels, where broken strands are sharp.

Measuring for a payoff or stand

If the reel will turn on equipment, add three numbers: arbor hole diameter, so the spindle fits; drive-hole spacing from the centre, so the drive pin lines up; and overall width outside the flanges, so the reel clears the stand's arms. A reel that fits on paper but has an oval arbor or a torn drive hole will still turn badly; check both while you have the tape out.

Recording a whole yard

A simple sheet with columns for flange, drum, traverse, build, maker name, reel number and condition is enough. Write one row per size group rather than per reel unless reels are returnable, in which case each numbered reel gets its own row. Photograph the sheet with the stack behind it and send both with the request.

Questions

What are standard cable reel dimensions?

There is no single standard, but common builds cluster by flange size; the size chart in the sizes guide gives typical drum and traverse ranges for each.

Do I need to measure every reel for a quote?

No. Flange sizes and a count, with photos, are enough.

What tools do I need?

A tape measure long enough for your biggest flange, and a phone for photos.

How do I measure a reel I can't stand upright?

Measure the flange across the face lying down, and traverse between the inner flange faces at the rim. Don't try to stand a large reel alone.

Reel words on this page

Flange

The round side discs that hold the cable in. Flange diameter, edge to edge, is the size a reel is known by.

Drum (barrel)

The cylinder between the flanges that the cable winds around.

Traverse

The inside width between the flanges: how wide a layer of cable can be.

Arbor hole

The centre hole a spindle, shaft or payoff bar passes through.

Drive hole

A smaller hole off-centre in the flange that a drive pin uses to turn the reel.

Lagging / staves

The boards nailed around the drum, and the protective boards sometimes nailed across the flanges over finished cable.