18 inch flange wooden reels

The two 18 inch reels that are actually published

Few makers print an 18 inch row. Of the size tables we read, two give one. Okonite's Reel Anatomy bulletin lists an 18x10x6: 18 inch flanges, a 10 inch traverse between them, a 6 inch drum, 11.5 inches out-to-out, 11 lb empty and rated for about 185 lb of cable. Corning's procedure for cutting and respooling fiber optic cable lists an 18x12x10 as one of its take-up reels.

Southwire's packaging sheet jumps from its 15.75 inch plywood reels to 23 inch nailed reels, and Anixter's NEMA capacity table goes from a 16 inch flange to a 20 inch one. So an 18 is a real size, but a thin one in the published record. When one comes across the desk it is usually a plywood reel, sometimes a light nailed reel, and it often arrives as part of a mixed small-reel lot rather than a lot of its own.

How many feet of wire fit on an 18

The approximate footage comes from the NEMA WC 26 formula as Anixter reprints it: Footage = 0.262 x T x (H - C) x (D + H - C) / d squared. T is the traverse, D the drum, d the cable's outside diameter, H the flange height above the drum, which is half of flange minus drum, and C the clearance left below the flange rim. Anixter's table uses 1 inch of clearance for 16 to 28 inch flanges, so that is what we used here.

On the 18x10x6, H is 6 inches, H - C is 5 and D + H - C is 11, so the reel's constant is 0.262 x 10 x 5 x 11, about 144. Divide that by the square of the cable diameter. On the 18x12x10, H is 4, H - C is 3 and D + H - C is 13, giving a constant of about 123. The bigger drum on the Corning reel costs footage, but it protects the cable's bend.

These are approximate figures. Real winds are rarely perfect, jacket sizes vary, and some plants leave more than an inch of clearance, so treat them as a check on whether a cut will fit, not a promise.

Why the 6 inch drum limits what goes on it

Footage is only half the question on a small reel. The other half is bend. Anixter's Table 10.1 gives NEMA WC 26 minimum drum diameters as multiples of the cable's outside diameter. Nonshielded cable up to 2,000 volts needs a drum at least 10 times its diameter, so a 6 inch drum tops out at about 0.6 inch cable. Tape shielded cable needs 14 to 20 times, interlocked armor 14 times and wire armored 16 times, which puts most armored and shielded cable off an 18x10x6 entirely.

Fiber is stricter. NEMA calls for 20 times the cable diameter and never less than 12 inches, and notes that some makers ask for 30 times. Corning's own rule is a drum of at least 8 inches or 30 times the cable diameter, whichever is larger; its appendix puts the minimum drum for an 8.5 mm cable at 10.0 inches. That is why Corning's 18 inch reel has a 10 inch drum, and why we don't send an 18x10x6 to anyone respooling fiber.

• Nonshielded, 0 to 2,000 V: 10x OD, so about 0.6 in cable on a 6 in drum
• Wire armored or flat tape armored: 16x OD, about 0.37 in on a 6 in drum
• Fiber optic: 20x OD and never under 12 in (NEMA); 30x or 8 in minimum (Corning)
• Corning's published capacities for its 18x12x10: about 1,115 ft at 0.36 in, 660 ft at 0.48 in, 460 ft at 0.60 in

Where 18s turn up and who wants them

An 18 is a counter reel. Electrical distributors use reels this size to hand an electrician a few hundred feet of a wire cut from a master reel. Fiber splicing and test crews use them to carry a respooled length back to the truck. Panel shops, sign shops and small motor rewind shops keep a few for control wire and lead wire. Rope and cordage sellers use them for retail cuts.

The empties gather in two places: the back of a distributor branch where returned cut reels pile up, and the corner of a contractor's shop where a job's leftover lengths were wound off and the reel was never sent anywhere. Neither place has a take-back route for them. Sonoco's EcoReel guide sets a 30 inch flange minimum for the reels it collects, and the manufacturer return programs we have read start at 30 inches or cover steel only.

Carrying, stacking and shipping an 18

At 11 lb empty, an 18x10x6 is a one-hand carry. Anixter's handling notes ask that reels be stored and shipped upright on both flanges, but they make an exception for reels under two feet in diameter and under 200 lb, so an 18 can be stacked flat, boxed or palletized. That is how they move: stacked on a pallet, banded and wrapped, as less-than-truckload freight, or mixed into a trailer of larger reels to fill the gaps.

Freight decides the economics. One 18 inch reel costs more to ship than it is worth, and a pallet of them costs about the same to move as a pallet of anything else. We quote small reels by the pallet or as part of a mixed reel lot, and we tell the buyer up front when a pallet is the smallest sensible order.

What to check on a used 18 before you buy or sell it

Small plywood reels fail in different places from big nailed ones. Look at these before a count goes on the paperwork.

• Arbor hole size. Anixter's small plywood reels have 1 1/2 inch arbor holes at 12 to 16 inch flanges and 2 inch holes at 24 to 30 inches; Southwire's nailed and plywood reels use 3.125 inches. Make sure it fits your payoff stand or spindle.
• Flange delamination. Plywood flanges that sat in rain split into layers at the rim; a lifted ply catches the wire on the wind.
• Drum surface. Staples or nail heads standing proud of the drum will cut insulation on the first wrap.
• Tie-off and start holes. On a small reel a torn start hole is a minor repair, but note it.
• Matching sizes. A lot of 18s that are really 16s, 18s and 20s mixed together is fine, but write the count for each size separately.

How we quote a lot of 18 inch reels

Give us the three numbers from the reel stencil or a tape, the count, whether they are plywood or nailed, and a photo of the stack. If you are selling, tell us whether they are palletized and whether a forklift is on site to load them. If you are buying, tell us the cable diameter and length you plan to wind so we can check the drum and the footage. Freight is quoted with the reels, because on reels this small it is most of the cost.