Reference
Sizes, gauges and what to record before you sell
Most wire quotes come down to a handful of facts that are printed on the reel tag or the jacket. Knowing which ones matter — and where to find them — turns a vague conversation into a firm answer.
This page covers the size range we buy, the difference between AWG and MCM, what the voltage class tells you, and how to read a reel tag when it is still legible.
AWG versus MCM
AWG — American Wire Gauge — runs in the opposite direction to intuition: #14 is smaller than #12, and #12 is smaller than #10. Above 4/0 the convention changes to circular mils, written as kcmil or MCM. 250 MCM is 250,000 circular mils. That is why a size list can jump from 4/0 straight to 250, 300, 350 and beyond.
When you are listing a lot, write the size exactly as it appears on the reel. If the tag says 4/0, do not convert it to 0000 — the buyer reading your list will recognize the tag format faster.
The size range we buy
| Size | Typical application | Common constructions |
|---|---|---|
| #14 | Lighting circuits, control wiring | THHN, XHHW, MTW |
| #12 | General branch circuits | THHN, THWN-2, MC |
| #10 | Branch circuits, small equipment | THHN, THWN-2, XHHW |
| #8 | Equipment and subpanel feeders | THHN, XHHW, SER |
| #6 | Feeders, ranges, subpanels | THHN, XHHW, SER, SOOW |
| #4 | Feeders and service conductors | THHN, XHHW, SER, SEU |
| #2 | Service and feeder conductors | THHN, XHHW, SER, SEU, URD |
| #1 | Service conductors and feeders | XHHW, SER, URD |
| 1/0 | Service entrance, feeders | XHHW, SER, SEU, URD |
| 2/0 | Service entrance, heavy feeders | XHHW, SER, URD, welding |
| 3/0 | Service and distribution feeders | XHHW, SER, URD, welding |
| 4/0 | Service and large feeders | XHHW, SER, URD, welding |
| 250 MCM | Large feeders and distribution | XHHW, tray, MV cable |
| 300 MCM | Large feeders and distribution | XHHW, tray, MV cable |
| 350 MCM | Service and distribution | XHHW, tray, MV cable |
| 400 MCM | Service and distribution | XHHW, tray, MV cable |
| 500 MCM | Heavy distribution | XHHW, tray, MV cable |
| 600 MCM | Heavy distribution | XHHW, tray, MV cable |
| 750 MCM | Industrial distribution | XHHW, tray, MV cable |
| 1000 MCM | Industrial distribution, substations | XHHW, tray, MV cable |
Voltage class
Voltage class separates everyday building wire from distribution cable. Most building, tray and control cable is rated 600V; power-limited tray and control cable is often 300V; medium voltage begins at 5kV and runs through 8kV, 15kV, 25kV, 35kV and 69kV and above. The class is printed on the jacket and normally appears on the reel tag.
Reading a reel tag
A legible tag usually carries the manufacturer, the wire type, the size, the voltage rating, the conductor count, the length in feet, and a lot or date code. Photograph the whole tag and, if the print is faded, a second shot at an angle with the light raking across it. The date code matters: cable manufactured decades ago is reviewed differently from cable made last year.
Conductor count and grounding
For multiconductor cable, the count is written as a sequence — 12/2 means two #12 conductors, 12/2 with ground adds a grounding conductor, and 4/0-4/0-2/0-2/0 describes a full service assembly. Tray and control cable may run 3 to 37 conductors. Getting the count right changes the value significantly, so photograph the cut end if the tag is unclear.
Condition language that helps
- New surplus — never unwrapped, tag intact
- Unused — opened but never installed
- Overstock — old inventory, possibly discontinued
- Cancelled project — ordered and never used
- Partial reel — opened and partly pulled
- De-energized — removed from service, history known
Questions
Common questions
What if the reel tag is missing?
The jacket print is the backup. Measure the conductor diameter if the print is gone entirely, photograph the cut end, and describe the insulation type as best you can. It makes the review slower but not impossible.
Does the manufacturer matter?
It is useful context but not decisive. Construction, size, footage and condition drive value far more than the brand name on the tag.
Should I include the reel itself in the weight?
No. Give the cable weight if you know it and note that it excludes the reel. Wooden reels vary widely in weight and are not part of what is being bought.
Next steps
Not sure whether your lot fits? A photo and a jacket print are usually enough for a straight answer.
Ready to move that surplus wire?
Send the reel details and photos. No cost to submit, and no obligation to accept a quote.