Copper content
How much copper is in Extension cords / SJ cord?
About 42% of its weight is recoverable copper. Here's what that means for stripping, grading, and what your yard will pay.
What Extension cords / SJ cord is
Also sold or searched as SJ/SJO cord, power cords, drop cords. Stranded fine copper under rubber. Cut off and sell the plugs' brass separately at some yards.
How much copper is inside
The copper recovery rate is the share of a cable's total weight that is actual copper once the insulation and jacket are stripped away. For Extension cords / SJ cord that's about 42%, and typically anywhere from 35% to 48% depending on gauge, age, and condition.
In round numbers: 100 lb of Extension cords / SJ cord yields roughly 42 lb of bare copper. At an example #1 copper price of $3.90/lb that's about $164 of copper — but prices swing by region and by the week, so run it with the number your own yard pays.
Open the Copper Wire Yield calculator, pick "Extension cords / SJ cord" (or type your own recovery %), and enter your local prices to see the stripped-vs-as-is breakdown for your exact load.
Strip it or sell it as-is?
Verdict for Extension cords / SJ cord: usually sell as-is unless you strip fast. Stripping only pays when the gap between the bare-copper price and the as-is (insulated) price beats the time it takes — and that gap scales with the recovery rate. At 42%, it is a judgement call that depends on your stripping speed. A machine tips it in your favor; a utility knife often does not.
To put a dollar figure on your own time, run it through the Strip or Sell calculator, which adds an hourly rate to the raw copper math.
How Extension cords / SJ cord compares to other cable
Where Extension cords / SJ cord sits against every other common cable type (its row is marked):
| Cable type | Recovery | Typical range |
|---|---|---|
| MCM / feeder cable (250 MCM+) | ~88% | 85–94% |
| THHN — heavy gauge (4 AWG to 4/0) | ~84% | 80–90% |
| THHN — standard (8–16 AWG) | ~80% | 75–88% |
| Double-insulated power wire | ~75% | 70–80% |
| Romex / NM-B (indoor solid) | ~65% | 62–70% |
| Mixed #2 insulated wire | ~60% | 55–69% |
| AC / appliance whip wire | ~55% | 50–60% |
| Extension cords / SJ cord ← this page | ~42% | 35–48% |
| Cat5/Cat6 — solid bulk runs | ~42% | 35–50% |
| Cat5/Cat6 patch cords (stranded) | ~22% | 18–28% |
| MC/BX armored cable (copper inside) | ~30% | 25–35% |
| Christmas lights | ~20% | 15–25% |
Sources
- Sahd Metal Recycling: 44% shop wire
- ScrapMonster: graded as its own low/mid category
Recovery figures are cross-checked against at least two published yard references and kept at the conservative end of each range, so surprises land in your favor. Measuring a stripped sample of your own cable always beats a table.
Extension cords / SJ cord: quick answers
How much copper is in Extension cords / SJ cord?
About 42% of its weight — usually 35–48% depending on gauge and condition. So 100 lb of Extension cords / SJ cord yields roughly 42 lb of bare copper once stripped.
Is Extension cords / SJ cord worth stripping?
Usually sell as-is unless you strip fast. At a ~42% recovery rate, stripping is a close call that depends on how fast you strip — use a machine, not a knife. Run your own prices through the Strip or Sell calculator to be sure.
What copper grade does Extension cords / SJ cord sell as?
Low-grade / shop wire as-is. Yards buy insulated wire as-is at a discounted "ICW" rate that already assumes an average recovery; stripping clean copper moves it up to a higher-paying bare-copper grade.
Price your own wire
Enter your yard's prices and see stripped vs as-is for this exact cable.