SPEC18 AWG at a glance
| Also called | 18 gauge |
|---|---|
| Conductor area | 1.62 kcmil · 0.823 mm² |
| Solid diameter | 0.04 in |
| Stranded (Class B) | 7 strands · 0.046 in |
| THHN/TFFN outside diameter | ≈ 0.084 in |
| Finished copper wire weight | ≈ 6 lb / 1,000 ft |
| Bare copper weight | ≈ 5 lb / 1,000 ft |
| Common put-ups | 500 ft spools · 2,500 ft reels of TFFN/MTW · multi-conductor control cable on 1,000 ft reels |
| Conductor | 60 °C | 75 °C | 90 °C |
|---|---|---|---|
| Fixture wire (NEC 402.5) | 6 A | ||
Dimensions from NEC Chapter 9 Tables 5 and 8. Weights are approximate and vary by manufacturer and insulation. For design, follow the NEC and a licensed electrician.
Wire types we buy in 18 AWG
01How to Identify 18 AWG Wire and Cable
Start with the jacket print and reel or spool label. Look for an 18 AWG conductor designation, the wire type, conductor metal, manufacturer and any footage information. Photograph the complete marking sequence rather than just the gauge. On multi-conductor cable, the outer jacket identifies the cable assembly; its overall diameter does not establish the gauge of each conductor.
18 gauge is an AWG designation, not an aught size or an MCM designation. MCM and kcmil describe conductor area, while aught naming applies to larger AWG sizes. Our wire gauge chart helps distinguish these naming systems when you have mixed inventory.
For this size, the solid conductor diameter is 0.04 inch. Class B construction has 7 strands and a conductor diameter of 0.046 inch. These are conductor measurements, not jacket measurements. Use diameter as a supporting check, not a substitute for legible markings, especially when insulation or a cable jacket remains in place.
02What the 18 AWG Specifications Mean
The conductor area for 18 AWG is 1.62 kcmil, equivalent to 0.823 mm². That area describes the conductor, not the finished cable. Solid and stranded constructions can share the same gauge while differing in diameter and flexibility. The supplied Class B construction uses 7 strands; do not assume every flexible 18 AWG product has that construction.
The approximate THHN/TFFN outside diameter is 0.084 inch. Actual product identification still depends on its markings and manufacturer information. A multi-conductor cable or portable cord has an overall diameter that includes additional insulation, fillers or jacket material.
The supplied fixture-current reference is 6 amperes. Treat it as a fixture-specific reference, not a general branch-circuit rating or a blanket allowance for every 18 AWG cable. NEC 310.16 is not a universal ampacity lookup for the products on this page. Have a licensed electrician or engineer confirm the applicable wiring rules, listing, temperature conditions and adjustments before selecting material for installation.
03Common Uses in Houston Construction and Plants
In Houston construction and plant work, 18 AWG commonly appears in control wiring rather than large power feeders. MTW and TFFN are associated with machine wiring and control-panel applications. Thermostat, relay and other low-current control circuits also use this conductor size, subject to the requirements of the particular system.
Multi-conductor control and instrumentation cables may remain after equipment changes, panel work or project closeout. Portable cord marked 18/2 or 18/3 SJOOW is another common form. Keep those product categories separate when preparing an inventory: similar conductor sizes do not make different cable constructions interchangeable.
For sellers across Greater Houston, the useful information is what the material actually is and how much remains. Retain reel tags, carton labels and jacket markings from jobsite or plant inventory. Describe whether the cable is unused stock or previously installed material. We review reusable surplus, but an intended application alone does not prove that a particular cable is suitable for reuse.
0418 AWG Wire Types We Buy
As 18 AWG wire buyers, we review several cable categories. Send the actual product designation rather than describing every item as small copper wire. We buy qualifying new, unused and reusable material in these categories:
- Tray cable with identifiable construction and usable remaining lengths.
- Control cable from surplus project, panel or plant inventory.
- Instrumentation cable, including identifiable multi-conductor assemblies.
- Portable cord, with the exact cord designation visible.
- Fire alarm cable with readable markings and sound packaging or coils.
Common put-ups include 500-foot spools, 2,500-foot reels of TFFN/MTW and multi-conductor control cable on 1,000-foot reels. Partial packages can also be reviewed; a full original reel is not required.
If you want to sell 18 gauge wire, photograph each distinct type separately. Include conductor count, shielding information where marked, and the condition of exposed ends. Surplus 18 AWG cable with intact identification is easier to evaluate than mixed, unmarked lengths.
05How Footage, Weight and Packaging Affect Value
18 AWG copper wire value depends on more than weight. We consider the conductor-metal market, cable type and demand, size, footage, manufacturer, date code, quantity, packaging condition and pickup logistics. Reusable material is usually worth more than its scrap melt value, but condition and identification matter.
For a simple estimate, finished THHN/THWN-2 copper wire weighs approximately 6 pounds per 1,000 feet. A net wire weight of approximately 6 pounds therefore suggests approximately 1,000 feet of that product. Exclude spool or reel weight. Do not apply that estimate to jacketed multi-conductor cable, whose insulation, jacket and other components change the weight relationship.
Bare stranded copper is approximately 5 pounds per 1,000 feet; bare aluminum is approximately 2 pounds per 1,000 feet. Our copper wire weight guide provides context for weight-based estimates. Send tag footage when available and label estimates honestly. Protected spools, secured coils and sound reels help preserve material for review.
06How to Sell 18 AWG Wire in Houston
Send photos of reel tags or jacket print, footage or weight, and your location to start. Text 951-403-5738 or email industrial832@gmail.com, or request a written offer. We review the information, provide a written offer, schedule pickup or drop-off, verify material on site and make payment per the written offer.
We serve Greater Houston only: Harris, Fort Bend, Montgomery, Brazoria, Galveston, Chambers and Waller counties. Pickup is scheduled at the seller’s site. Tell us about access restrictions, where the material is stored and any handling needs for heavy reels so those details can be considered before scheduling.
Drop-off is by appointment only at 6402 McGrew St, Houston, TX 77087, in southeast Houston’s Mayfair area near I-45 and I-610. Call first before loading or driving over. Keep each wire type separated and its identifying tag attached. Do not remove insulation simply to prepare reusable wire for sale.
FAQQuestions sellers ask
Can you review 18 AWG wire with an unreadable spool label?
Yes, send clear photos of any remaining jacket print and the material itself. A missing spool label does not automatically rule it out, but we need enough information to identify the product and assess reuse. Do not guess at the wire type or manufacturer; tell us which details are unknown.
Should I combine short 18 AWG pieces into one coil?
Keep separate lengths separate and describe their condition. Combining pieces can make a coil look like one continuous run when it is not. Short, burned, cut or heavily damaged wire may be better suited to scrap. We focus on reusable material and will tell you what we consider reusable.
Do older date codes make unused 18 AWG cable unsellable?
Not automatically. Manufacturer and date code are part of our review, along with storage condition, identification and current demand. Photograph the date code and disclose any known exposure to moisture, heat or physical damage. Unused status alone does not establish that insulation or the complete cable remains suitable for reuse.
Can I sell a mixed lot of 18 AWG copper and aluminum wire?
We review both copper and aluminum surplus. Identify the conductor metal for each item where markings or documentation establish it, and keep the materials separated. Include an inventory of the different products rather than one combined description. Metal, construction and condition can affect how each portion of the lot is evaluated.
Is Houston Wire Buyers affiliated with Houston Wire & Cable Company?
No. Houston Wire Buyers is not affiliated with Houston Wire & Cable Company or any manufacturer. We buy surplus wire from sellers within Greater Houston. When contacting us about 18 AWG material, include your own inventory photos and location so we can review the specific wire you want to sell.