SOOW, SJOOW, SEOOW, STOOW, SJT. Portable cord part numbers look like alphabet soup until you learn that every letter answers one question about the cord. Once you can read them, picking the right cord takes about ten seconds. Here's the decoder.
What Each Letter Means
| Letter | Meaning |
|---|---|
| S | Service cord, rated 600V (hard service) |
| SJ | Junior service, rated 300V (lighter build) |
| E | Elastomer (TPE) jacket instead of thermoset rubber |
| T | Thermoplastic (PVC) construction |
| O | Oil-resistant jacket |
| OO | Oil-resistant jacket and oil-resistant insulation |
| W | Weather and water resistant, rated for outdoor use |
Read any cord type left to right and it describes itself. SJOOW is junior service (300V), oil-resistant inside and out, outdoor rated. STOOW is hard service (600V), thermoplastic, oil-resistant inside and out, outdoor rated. That's the whole system.
The Common Types, Compared
| Type | Voltage | Jacket | Where it earns its keep |
|---|---|---|---|
| SOOW | 600V | Thermoset rubber (EPDM/CPE) | The industrial standard: tools, pumps, temporary power, motors |
| SJOOW | 300V | Thermoset rubber | Lighter-duty versions of the same jobs; smaller and cheaper |
| SEOOW | 600V | TPE elastomer | Cold-weather work; stays flexible well below freezing |
| STOOW | 600V | Thermoplastic (PVC) | Budget-friendly hard service where extreme cold isn't a factor |
| SJT | 300V | Thermoplastic (PVC) | Light duty: appliances, office equipment, shop lights |
How to Choose in Practice
Start with voltage. If the equipment runs at more than 300V, or you just want one cord family for everything, stay in the S types (600V). The SJ types cover light commercial and residential duty at a lower price and smaller diameter.
Then match the jacket to the environment. Thermoset rubber (SOOW, SJOOW) takes abrasion and weld spatter best and is the default for job sites. TPE (SEOOW) stays flexible in freezers and winter job sites where rubber stiffens up. PVC (STOOW, SJT) costs less and works fine indoors and in mild conditions.
Oil matters more than people think. The double O is cheap insurance around machine shops, garages, and food plants where cords lie in whatever's on the floor. A single-O or no-O cord in an oily environment swells, softens, and cracks.
What About Bigger Loads?
Portable cord tops out at 2 AWG. When a generator feed or distribution run needs more copper or more than 600V, you're shopping for portable power cable instead: Type W or DLO. Our Type W vs SOOW comparison covers where that line sits and why.
Stock and Cut to Length
We stock SOOW, SJOOW, and the rest of the portable cord family in standard gauges and conductor counts, cut to the length your job needs. If a spec sheet calls for a type you don't see on the site, ask. Odds are good we can get it.
