What's the difference between S and SJ service cord?

[randy1]

Guys,
What's the difference between S and SJ service cord? Do I need to specify either of these when I am ordering. I am looking to extend power cords on 120V machinery. thanks!

[Cheller]

The service cord letters in these cable type designations are so you can determine cable characteristics. They are based on UL and the National Electrical Code. Service cord comes in many shapes and sizes.

Here's a list of the types of service cord I found on Mcmaster's website:

S—Standard cord: rated at 600V AC

SJ—Junior cord: rated at 300V AC

E—Elastomer: thermoplastic rubber coating

T—Thermoplastic coating

O—Oil Resistant insulation on the outside only

OO—Oil Resistant Inner and Outer Insulation

W—Approved for Outdoor use (not sure if it qualifies as waterproof)

[3rdshiftguy]

Type S and Type SJ cord are the most common cord that I have worked with. The difference being the rated voltage and the overall cord diameter.